ST ST7LITES2Y0, ST7LITES5Y0, ST7LITE02Y0, ST7LITE05Y0, ST7LITE09Y0 User Manual

8-bit microcontroller with single voltage
Flash memory, data EEPROM, ADC, timers, SPI
Memories
– 1K or 1.5 Kbytes single voltage Flash Pro-
gram memory with read-out protection, In-Cir­cuit and In-Application Programming (ICP and IAP). 10 K write/erase cycles guaranteed,
data retention: 20 years at 55 °C. – 128 bytes RAM. – 128 bytes data EEPROM with read-out pro-
tection. 300K write/erase cycles guaranteed,
data retention: 20 years at 55 °C.
Clock, Reset and Supply Management
– 3-level low voltage supervisor (LVD) and aux-
iliary voltage detector (AVD) for safe power-
on/off procedures – Clock sources: internal 1MHz RC 1% oscilla-
tor or external clock – PLL x4 or x8 for 4 or 8 MHz internal clock – Four Power Saving Modes: Halt, Active-Halt,
Wait and Slow
Interrupt Management
– 10 interrupt vectors plus TRAP and RESET – 4 external interrupt lines (on 4 vectors)
I/O Ports
– 13 multifunctional bidirectional I/O lines – 9 alternate function lines – 6 high sink outputs
2 Timers
– One 8-bit Lite Timer (LT) with prescaler in-
cluding: watchdog, 1 realtime base and 1 in-
put capture.

ST7LITE0xY0, ST7LITESxY0

SO16
DIP16
QFN20
– One 12-bit Auto-reload Timer (AT) with output
compare function and PWM
1 Communication Interface
– SPI synchronous serial interface
A/D Converter
– 8-bit resolution for 0 to V – Fixed gain Op-amp for 11-bit resolution in 0 to
250 mV range (@ 5V V
DD
– 5 input channels
Instruction Set
– 8-bit data manipulation – 63 basic instructions with illegal opcode de-
tection – 17 main addressing modes – 8 x 8 unsigned multiply instruction
Development Tools
– Full hardware/software development package
150”
DD
)
Device Summary
Features
Program memory - bytes 1K 1K 1.5K 1.5K 1.5K RAM (stack) - bytes 128 (64) 128 (64) 128 (64) 128 (64) 128 (64) Data EEPROM - bytes----128
Peripherals
Operating Supply 2.4V to 5.5V CPU Frequency 1MHz RC 1% + PLLx4/8MHz Operating Temperature -40°C to +85°C Packages SO16 150”, DIP16, QFN20
ST7LITESxY0 (ST7SUPERLITE) ST7LITE0xY0
ST7LITES2Y0 ST7LITES5Y0 ST7LITE02Y0 ST7LITE05Y0 ST7LITE09Y0
LT Timer w/ Wdg,
AT Timer w/ 1 PWM,
SPI
LT Timer w/ Wdg,
AT Timer w/ 1 PWM,
SPI, 8-bit ADC
LT Timer w/ Wdg,
AT Timer w/ 1 PWM,
SPI
LT Timer w/ Wdg,
AT Timer w/ 1 PWM, SPI,
8-bit ADC w/ Op-Amp
Rev 6
November 2007 1/124
1
Table of Contents
ST7LITE0xY0, ST7LITESxY0 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 REGISTER & MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 FLASH PROGRAM MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3 PROGRAMMING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.4 ICC INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.5 MEMORY PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.6 RELATED DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.7 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5 DATA EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3 MEMORY ACCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.4 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.5 ACCESS ERROR HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.6 DATA EEPROM READ-OUT PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.7 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6 CENTRAL PROCESSING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3 CPU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7 SUPPLY, RESET AND CLOCK MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.1 INTERNAL RC OSCILLATOR ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.2 PHASE LOCKED LOOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.3 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.4 RESET SEQUENCE MANAGER (RSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
8 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8.1 NON MASKABLE SOFTWARE INTERRUPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8.2 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8.3 PERIPHERAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8.4 SYSTEM INTEGRITY MANAGEMENT (SI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
9.2 SLOW MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
9.3 WAIT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9.4 ACTIVE-HALT AND HALT MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
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10 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
10.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
10.2 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
10.3 UNUSED I/O PINS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
10.4 LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
10.5 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
10.6 I/O PORT IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
11 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
11.1 LITE TIMER (LT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
11.2 12-BIT AUTORELOAD TIMER (AT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
11.3 SERIAL PERIPHERAL INTERFACE (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
11.4 8-BIT A/D CONVERTER (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
12 INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
12.1 ST7 ADDRESSING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
12.2 INSTRUCTION GROUPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
13 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
13.1 PARAMETER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
13.2 ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
13.3 OPERATING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
13.4 SUPPLY CURRENT CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
13.5 CLOCK AND TIMING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
13.6 MEMORY CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
13.7 EMC (ELECTROMAGNETIC COMPATIBILITY) CHARACTERISTICS . . . . . . . . . . . . . 93
13.8 I/O PORT PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
13.9 CONTROL PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
13.10 COMMUNICATION INTERFACE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . 102
13.11 8-BIT ADC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
14 PACKAGE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
14.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
14.2 THERMAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
15 DEVICE CONFIGURATION AND ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . 112
15.1 OPTION BYTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
15.2 DEVICE ORDERING INFORMATION AND TRANSFER OF CUSTOMER CODE . . . . 114
15.3 DEVELOPMENT TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
15.4 ST7 APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
16 KNOWN LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
16.1 EXECUTION OF BTJX INSTRUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
16.2 IN-CIRCUIT PROGRAMMING OF DEVICES PREVIOUSLY PROGRAMMED WITH HARD­WARE WATCHDOG OPTION 121
16.3 IN-CIRCUIT DEBUGGING WITH HARDWARE WATCHDOG . . . . . . . . . . . . . . . . . . . 121
16.4 RECOMMENDATIONS WHEN LVD IS ENABLED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
16.5 CLEARING ACTIVE INTERRUPTS OUTSIDE INTERRUPT ROUTINE . . . . . . . . . . . . 121
17 REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
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Table of Contents
To obtain the most recent version of this datasheet,
please check at www.st.com
Please also pay special attention to the Section “KNOWN LIMITATIONS” on page 121.
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1 DESCRIPTION

ST7LITE0xY0, ST7LITESxY0
The ST7LITE0x and ST7SUPERLITE (ST7LITESx) are members of the ST7 microcon­troller family. All ST7 devices are based on a com­mon industry-standard 8-bit core, featuring an en­hanced instruction set.
The ST7LITE0x and ST7SUPERLITE feature FLASH memory with byte-by-byte In-Circuit Pro­gramming (ICP) and In-Application Programming (IAP) capability.
Under software control, the ST7LITE0x and ST7SUPERLITE devices can be placed in WAIT, SLOW, or HALT mode, reducing power consump­tion when the application is in idle or standby state.
Figure 1. General Block Diagram
Internal CLOCK
V
V
RESET
DD
SS
1 MHz. RC OSC
+
PLL x 4 or x 8
LVD/AVD
POWER SUPPLY
CONTROL
The enhanced instruction set and addressing modes of the ST7 offer both power and flexibility to software developers, enabling the design of highly efficient and compact application code. In addition to standard 8-bit data management, all ST7 micro­controllers feature true bit manipulation, 8x8 un­signed multiplication and indirect addressing modes.
For easy reference, all parametric data are located in section 13 on page 81.
LITE TIMER
w/ WATCHDOG
PORT A
ADDRESS AND DATA BUS
12-BIT AUTO-
RELOAD TIMER
PA7:0
(8 bits)
8-BIT CORE
ALU
FLASH
MEMORY
(1 or 1.5K Bytes)
RAM
(128 Bytes)
DATA EEPROM
(128 Bytes)
SPI
PORT B
8-BIT ADC
PB4:0
(5 bits)
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ST7LITE0xY0, ST7LITESxY0

2 PIN DESCRIPTION

Figure 2. 20-Pin QFN Package Pinout
RESET
NC
NC
NC
MISO/AIN2/PB2
SCK/AIN1/PB1
DD
V
PB0/SS/AIN0
1
2
3
4
5
ei2
6
78 910
ei1
SS
PA0 (HS)/LTIC
V
17181920
16
e0e3
PA1 (HS)
15
PA2 (HS)/ATPWM0
PA3 (HS)
14
NC
13
12
PA4 (HS)
11
PA5 (HS)/ICCDATA
MOSI/AIN3/PB3
Figure 3. 16-Pin SO and DIP Package Pinout
k
V
V
RESET
SS/AIN0/PB0
SCK/AIN1/PB1 MISO/AIN2/PB2 MOSI/AIN3/PB3
CLKIN/AIN4/PB4
SS
DD
1
2
3
4
5
6
7
8
PA7
CLKIN/AIN4/PB4
ei3
ei2
MCO/ICCCLK/PA6
ei0
ei1
PA0 (HS)/LTIC
16
PA1 (HS)
15
PA2 (HS)/ATPWM0
14
PA3 (HS)
13
PA4 (HS)
12
PA5 (HS)/ICCDATA
11
PA6/MCO/ICCCLK
10
PA7
9
(HS) 20mA High sink capability eix associated external interrupt vector
(HS) 20mA high sink capability eixassociated external interrupt vector
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PIN DESCRIPTION (Cont’d) Legend / Abbreviations for Table 1:
Type: I = input, O = output, S = supply In/Output level: C= CMOS 0.15V
= CMOS 0.3VDD/0.7VDD with input trigger
C
T
/0.85VDD with input trigger
DD
Output level: HS = 20mA high sink (on N-buffer only) Port and control configuration:
– Input: float = floating, wpu = weak pull-up, int = interrupt – Output: OD = open drain, PP = push-pull
Table 1. Device Pin Description
ST7LITE0xY0, ST7LITESxY0
1)
, ana = analog
Pin n°
Pin Name
Type
QFN20
SO16/DIP16
18 1 V
19 2 V
1 3 RESET
SS
DD
I/O C
20 4 PB0/AIN0/SS
S Ground
S Main power supply
I/O C
6 5 PB1/AIN1/SCK I/O C
5 6 PB2/AIN2/MISO I/O C
7 7 PB3/AIN3/MOSI I/O C
8 8 PB4/AIN4/CLKIN I/O C
9 9 PA7 I/O C
10 10
11 11
PA6 /MCO/ ICCCLK
PA5/ ICCDATA
I/O C
I/O C
12 12 PA4 I/O C
14 13 PA3 I/O C
Level Port / Control
Main
Function
(after reset)
PP
Alternate Function
ADC Analog Input 0 or SPI Slave Select (active low)
Input
Input Output
Output
float
T
X ei3 X X X Port B0
T
wpu
int
ana
OD
X X Top priority non maskable interrupt (active low)
ADC Analog Input 1 or SPI Clock
Caution: No negative current in-
X XXXXPort B1
T
jection allowed on this pin. For details, refer to section 13.2.2 on
page 82
X XXXXPort B2
T
X ei2 X X X Port B3
T
X XXXXPort B4
T
X ei1 X X Port A7
T
ADC Analog Input 2 or SPI Mas­ter In/ Slave Out Data
ADC Analog Input 3 or SPI Mas­ter Out / Slave In Data
ADC Analog Input 4 or External clock input
Main Clock Output/In Circuit Communication Clock. Caution: During normal opera­tion this pin must be pulled- up, internally or externally (external
X X XXPort A6
T
pull-up of 10k mandatory in noisy environment). This is to avoid en­tering ICC mode unexpectedly during a reset. In the application, even if the pin is configured as output, any reset will put it back in input pull-up
HS X XXXPort A5 In Circuit Communication Data
T
HS X XXXPort A4
T
HS X XXXPort A3
T
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ST7LITE0xY0, ST7LITESxY0
Pin n°
Pin Name
QFN20
SO16/DIP16
15 14 PA2/ATPWM0 I/O CTHS X XXXPort A2 Auto-Reload Timer PWM0
16 15 PA1 I/O C
17 16 PA0/LTIC I/O C
Level Port / Control
Input Output
Type
Input
Output
float
HS X XXXPort A1
T
HS X ei0 X X Port A0 Lite Timer Input Capture
T
int
wpu
OD
ana
Main
Function
(after reset)
PP
Alternate Function
Note:
In the interrupt input column, “ei
” defines the associated external interrupt vector. If the weak pull-up col-
x
umn (wpu) is merged with the interrupt column (int), then the I/O configuration is pull-up interrupt input, else the configuration is floating interrupt input.
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3 REGISTER & MEMORY MAP

ST7LITE0xY0, ST7LITESxY0
As shown in Figure 4 and Figure 5, the MCU is ca­pable of addressing 64K bytes of memories and I/ O registers.
The available memory locations consist of up to 128 bytes of register locations, 128 bytes of RAM, 128 bytes of data EEPROM and up to 1.5 Kbytes of user program memory. The RAM space in­cludes up to 64 bytes for the stack from 0C0h to 0FFh.
Figure 4. Memory Map (ST7LITE0x)
0000h
007Fh 0080h
00FFh
0100h
0FFFh
1000h
107Fh 1080h
HW Registers
(see Table 2)
RAM
(128 Bytes)
Reserved
Data EEPROM
(128 Bytes)
0080h
00BFh 00C0h
00FFh
The highest address bytes contain the user reset and interrupt vectors.
The size of Flash Sector 0 is configurable by Op­tion byte.
IMPORTANT: Memory locations marked as “Re­served” must never be accessed. Accessing a re­served area can have unpredictable effects on the device.
Short Addressing RAM (zero page)
64 Bytes Stack
1000h
1001h
see section 7.1 on page 24
RCCR0
RCCR1
F9FFh FA00h
FFDFh
FFE0h
FFFFh
Reserved
Flash Memory
(1.5K)
Interrupt & Reset Vectors
(see Table 6)
PROGRAM MEMORY
FA00h
FBFFh FC00h
FFFFh
1.5K FLASH
0.5 Kbytes
SECTOR 1
1 Kbytes
SECTOR 0
FFDEh
RCCR0
FFDFh
RCCR1
see section 7.1 on page 24
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ST7LITE0xY0, ST7LITESxY0
REGISTER AND MEMORY MAP (Cont’d)
Figure 5. Memory Map (ST7SUPERLITE)
0000h
007Fh 0080h
00FFh
0100h
FBFFh FC00h
FFDFh
FFE0h
FFFFh
HW Registers
(see Table 2)
RAM
(128 Bytes)
Reserved
Flash Memory
(1K)
Interrupt & Reset Vectors
(see Table 6)
FC00h
FDFFh
FE00h
FFFFh
0080h
00BFh 00C0h
00FFh
Short Addressing RAM (zero page)
64 Bytes Stack
1K FLASH
PROGRAM MEMORY
0.5 Kbytes
SECTOR 1
0.5 Kbytes
SECTOR 0
FFDEh
FFDFh
see section 7.1 on page 24
RCCR0
RCCR1
10/124
1
REGISTER AND MEMORY MAP (Cont’d)
Legend: x=undefined, R/W=read/write
Table 2. Hardware Register Map
ST7LITE0xY0, ST7LITESxY0
Address Block
0000h 0001h 0002h
0003h 0004h 0005h
0006h to
000Ah
000Bh 000Ch
000Dh 000Eh 000Fh 0010h 0011h 0012h 0013h
0014h to
0016h
0017h 0018h
Port A
Port B
LITE
TIMER
AUTO-RELOAD
TIMER
AUTO-RELOAD
TIMER
Register
Label
PADR PADDR PAOR
PBDR PBDDR PBOR
LTCSR LTICR
ATCSR CNTRH CNTRL ATRH ATRL PWMCR PWM0CSR
DCR0H DCR0L
Register Name
Port A Data Register Port A Data Direction Register Port A Option Register
Port B Data Register Port B Data Direction Register Port B Option Register
Reserved area (5 bytes)
Lite Timer Control/Status Register Lite Timer Input Capture Register
Timer Control/Status Register Counter Register High Counter Register Low Auto-Reload Register High Auto-Reload Register Low PWM Output Control Register PWM 0 Control/Status Register
Reserved area (3 bytes)
PWM 0 Duty Cycle Register High PWM 0 Duty Cycle Register Low
Reset
Status
1)
00h
00h 40h
1)
E0h
00h 00h
xxh xxh
00h 00h 00h 00h 00h 00h 00h
00h 00h
Remarks
R/W R/W R/W
R/W R/W
2)
R/W
R/W Read Only
R/W Read Only Read Only R/W R/W R/W R/W
R/W R/W
0019h to
002Eh
0002Fh FLASH FCSR Flash Control/Status Register 00h R/W
00030h EEPROM EECSR Data EEPROM Control/Status Register 00h R/W
0031h 0032h 0033h
0034h 0035h 0036h
0037h ITC EICR External Interrupt Control Register 00h R/W
0038h 0039h
SPI
ADC
CLOCKS
SPIDR SPICR SPICSR
ADCCSR ADCDR ADCAMP
MCCSR RCCR
SPI Data I/O Register SPI Control Register SPI Control/Status Register
A/D Control Status Register A/D Data Register A/D Amplifier Control Register
Main Clock Control/Status Register RC oscillator Control Register
Reserved area (22 bytes)
xxh 0xh 00h
00h 00h 00h
00h FFh
R/W R/W R/W
R/W Read Only R/W
R/W R/W
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1
ST7LITE0xY0, ST7LITESxY0
Address Block
003Ah SI SICSR System Integrity Control/Status Register 0xh R/W
003Bh to
007Fh
Register
Label
Register Name
Reserved area (69 bytes)
Reset
Status
Remarks
Notes:
1. The contents of the I/O port DR registers are readable only in output configuration. In input configura-
tion, the values of the I/O pins are returned instead of the DR register contents.
2. The bits associated with unavailable pins must always keep their reset value.
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1

4 FLASH PROGRAM MEMORY

ST7LITE0xY0, ST7LITESxY0

4.1 Introduction

The ST7 single voltage extended Flash (XFlash) is a non-volatile memory that can be electrically erased and programmed either on a byte-by-byte basis or up to 32 bytes in parallel.
The XFlash devices can be programmed off-board (plugged in a programming tool) or on-board using In-Circuit Programming or In-Application Program­ming.
The array matrix organisation allows each sector to be erased and reprogrammed without affecting other sectors.

4.2 Main Features

ICP (In-Circuit Programming)
IAP (In-Application Programming)
ICT (In-Circuit Testing) for downloading and
executing user application test patterns in RAM
Sector 0 size configurable by option byte
Read-out and write protection

4.3 PROGRAMMING MODES

The ST7 can be programmed in three different ways:
– Insertion in a programming tool. In this mode,
FLASH sectors 0 and 1, option byte row and data EEPROM can be programmed or erased.
– In-Circuit Programming. In this mode, FLASH
sectors 0 and 1, option byte row and data EEPROM can be programmed or erased with­out removing the device from the application board.
– In-Application Programming. In this mode,
sector 1 and data EEPROM can be pro­grammed or erased without removing the de­vice from the application board and while the application is running.

4.3.1 In-Circuit Programming (ICP)

ICP uses a protocol called ICC (In-Circuit Commu­nication) which allows an ST7 plugged on a print­ed circuit board (PCB) to communicate with an ex­ternal programming device connected via cable. ICP is performed in three steps:
Switch the ST7 to ICC mode (In-Circuit Communi­cations). This is done by driving a specific signal sequence on the ICCCLK/DATA pins while the RESET pin is pulled low. When the ST7 enters ICC mode, it fetches a specific RESET vector which points to the ST7 System Memory contain­ing the ICC protocol routine. This routine enables the ST7 to receive bytes from the ICC interface.
– Download ICP Driver code in RAM from the
ICCDATA pin
– Execute ICP Driver code in RAM to program
the FLASH memory
Depending on the ICP Driver code downloaded in RAM, FLASH memory programming can be fully customized (number of bytes to program, program locations, or selection of the serial communication interface for downloading).

4.3.2 In Application Programming (IAP)

This mode uses an IAP Driver program previously programmed in Sector 0 by the user (in ICP mode).
This mode is fully controlled by user software. This allows it to be adapted to the user application, (us­er-defined strategy for entering programming mode, choice of communications protocol used to fetch the data to be stored etc.) IAP mode can be used to program any memory ar­eas except Sector 0, which is write/erase protect­ed to allow recovery in case errors occur during the programming operation.
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1
ST7LITE0xY0, ST7LITESxY0
FLASH PROGRAM MEMORY (Cont’d)

4.4 ICC interface

ICP needs a minimum of 4 and up to 6 pins to be connected to the programming tool. These pins are:
– RESET –V
: device reset
: device power supply ground
SS
– ICCCLK: ICC output serial clock pin – ICCDATA: ICC input serial data pin – CLKIN: main clock input for external source
: application board power supply (option-
–V
DD
al, see Note 3)
Notes:
1. If the ICCCLK or ICCDATA pins are only used as outputs in the application, no signal isolation is necessary. As soon as the Programming Tool is plugged to the board, even if an ICC session is not in progress, the ICCCLK and ICCDATA pins are not available for the application. If they are used as inputs by the application, isolation such as a serial resistor has to be implemented in case another de­vice forces the signal. Refer to the Programming Tool documentation for recommended resistor val­ues.
2. During the ICP session, the programming tool must control the RESET
pin. This can lead to con­flicts between the programming tool and the appli­cation reset circuit if it drives more than 5mA at
Figure 6. Typical ICC Interface
high level (push pull output or pull-up resistor<1K). A schottky diode can be used to isolate the appli­cation RESET circuit in this case. When using a classical RC network with R>1K or a reset man­agement IC with open drain output and pull-up re­sistor>1K, no additional components are needed. In all cases the user must ensure that no external reset is generated by the application during the ICC session.
3. The use of Pin 7 of the ICC connector depends on the Programming Tool architecture. This pin must be connected when using most ST Program­ming Tools (it is used to monitor the application power supply). Please refer to the Programming Tool manual.
4. Pin 9 has to be connected to the CLKIN pin of the ST7 when the clock is not available in the ap­plication or if the selected clock option is not pro­grammed in the option byte.
Caution: During normal operation, ICCCLK pin must be pulled- up, internally or externally (exter­nal pull-up of 10K mandatory in noisy environ­ment). This is to avoid entering ICC mode unex­pectedly during a reset. In the application, even if the pin is configured as output, any reset will put it back in input pull-up.
APPLICATION POWER SUPPLY
14/124
(See Note 3)
VDD
OPTIONAL (See Note 4)
CLKIN
ST7
PROGRAMMING TOOL
ICC CONNECTOR
ICC Cable
ICC CONNECTOR
HE10 CONNECTOR TYPE
975 3
1
246810
RESET
ICCCLK
ICCDATA
APPLICATION BOARD
APPLICATION RESET SOURCE
See Note 2
See Note 1 and Caution See Note 1
APPLICATION
I/O
1
FLASH PROGRAM MEMORY (Cont’d)
ST7LITE0xY0, ST7LITESxY0

4.5 Memory Protection

There are two different types of memory protec­tion: Read Out Protection and Write/Erase Protec­tion which can be applied individually.

4.5.1 Read out Protection

Readout protection, when selected provides a pro­tection against program memory content extrac­tion and against write access to Flash memory. Even if no protection can be considered as totally unbreakable, the feature provides a very high level of protection for a general purpose microcontroller. Both program and data E
2
memory are protected.
In flash devices, this protection is removed by re­programming the option. In this case, both pro­gram and data E
2
memory are automatically
erased, and the device can be reprogrammed. Read-out protection selection depends on the de-
vice type: – In Flash devices it is enabled and removed
through the FMP_R bit in the option byte.
– In ROM devices it is enabled by mask option
specified in the Option List.

4.5.2 Flash Write/Erase Protection

Write/erase protection, when set, makes it impos­sible to both overwrite and erase program memo­ry. It does not apply to E
2
data. Its purpose is to provide advanced security to applications and pre­vent any change being made to the memory con­tent.
Warning: Once set, Write/erase protection can never be removed. A write-protected flash device is no longer reprogrammable.
Write/erase protection is enabled through the FMP_W bit in the option byte.

4.6 Related Documentation

For details on Flash programming and ICC proto­col, refer to the ST7 Flash Programming Refer­ence Manual and to the ST7 ICC Protocol Refer­ence Manual
.

4.7 Register Description

FLASH CONTROL/STATUS REGISTER (FCSR)
Read/Write Reset Value: 000 0000 (00h) 1st RASS Key: 0101 0110 (56h) 2nd RASS Key: 1010 1110 (AEh)
70
00000OPTLATPGM
Note: This register is reserved for programming using ICP, IAP or other programming methods. It controls the XFlash programming and erasing op­erations.
When an EPB or another programming tool is used (in socket or ICP mode), the RASS keys are sent automatically.
Table 3. FLASH Register Map and Reset Values
Address
(Hex.)
002Fh
Register
Label
FCSR
Reset Value
76543210
00000
OPT
0
LAT
0
PGM
0
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ST7LITE0xY0, ST7LITESxY0

5 DATA EEPROM

5.1 INTRODUCTION

The Electrically Erasable Programmable Read Only Memory can be used as a non-volatile back­up for storing data. Using the EEPROM requires a basic access protocol described in this chapter.
Figure 7. EEPROM Block Diagram
EECSR
ADDRESS DECODER
0 E2LAT00 0 0 0 E2PGM
4
DECODER
ROW

5.2 MAIN FEATURES

Up to 32 bytes programmed in the same cycle
EEPROM mono-voltage (charge pump)
Chained erase and programming cycles
Internal control of the global programming cycle
duration
WAIT mode management
Read-out protection
HIGH VOLTAGE
PUMP
EEPROM
MEMORY MATRIX
(1 ROW = 32 x 8 BITS)
ADDRESS BUS
128128
4
4
DATA
MULTIPLEXER
DATA BUS
32 x 8 BITS
DATA LATCHES
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1
DATA EEPROM (Cont’d)
ST7LITE0xY0, ST7LITESxY0

5.3 MEMORY ACCESS

The Data EEPROM memory read/write access modes are controlled by the E2LAT bit of the EEP­ROM Control/Status register (EECSR). The flow­chart in Figure 8 describes these different memory access modes.
Read Operation (E2LAT = 0)
The EEPROM can be read as a normal ROM loca­tion when the E2LAT bit of the EECSR register is cleared.
On this device, Data EEPROM can also be used to execute machine code. Take care not to write to the Data EEPROM while executing from it. This would result in an unexpected code being execut­ed.
Write Operation (E2LAT = 1)
To access the write mode, the E2LAT bit has to be set by software (the E2PGM bit remains cleared). When a write access to the EEPROM area occurs,
Figure 8. Data EEPROM Programming Flowchart
READ MODE
E2LAT = 0
E2PGM = 0
the value is latched inside the 32 data latches ac­cording to its address.
When PGM bit is set by the software, all the previ­ous bytes written in the data latches (up to 32) are programmed in the EEPROM cells. The effective high address (row) is determined by the last EEP­ROM write sequence. To avoid wrong program­ming, the user must take care that all the bytes written between two programming sequences have the same high address: Only the five Least Significant Bits of the address can change.
At the end of the programming cycle, the PGM and LAT bits are cleared simultaneously.
Note: Care should be taken during the program­ming cycle. Writing to the same memory location will over-program the memory (logical AND be­tween the two write access data result) because the data latches are only cleared at the end of the programming cycle and by the falling edge of the E2LAT bit. It is not possible to read the latched data. This note is illustrated by the Figure 10.
WRITE MODE
E2LAT = 1
E2PGM = 0
READ BYTES
IN EEPROM AREA
CLEARED BY HARDWARE
WRITEUPTO32BYTES
(with the same 11 MSB of the address)
IN EEPROM AREA
START PROGRAMMING CYCLE
E2PGM=1 (set by software)
E2LAT=1
01
E2LAT
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1
ST7LITE0xY0, ST7LITESxY0
DATA EEPROM (Cont’d)
2
Figure 9. Data E
DEFINITION
PROM Write Operation
Row / Byte 0 1 2 3 ... 30 31 Physical Address
ROW
0
1
...
N
00h...1Fh 20h...3Fh
Nx20h...Nx20h+1Fh
E2LAT bit
E2PGM bit
Read operation impossible
Byte 1 Byte 2 Byte 32
PHASE 1
Writing data latches Waiting E2PGM and E2LAT to fall
Set by USER application
Programming cycle
PHASE 2
Read operation possible
Cleared by hardware
Note: If a programming cycle is interrupted (by RESET action), the integrity of the data in memory will not be guaranteed.
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1
DATA EEPROM (Cont’d)
ST7LITE0xY0, ST7LITESxY0

5.4 POWER SAVING MODES

Wait mode
The DATA EEPROM can enter WAIT mode on ex­ecution of the WFI instruction of the microcontrol­ler or when the microcontroller enters Active Halt mode.The DATA EEPROM will immediately enter this mode if there is no programming in progress, otherwise the DATA EEPROM will finish the cycle and then enter WAIT mode.
Active Halt mode
Refer to Wait mode.
Halt mode
The DATA EEPROM immediately enters HALT mode if the microcontroller executes the HALT in­struction. Therefore the EEPROM will stop the function in progress, and data may be corrupted.

5.5 ACCESS ERROR HANDLING

If a read access occurs while E2LAT = 1, then the data bus will not be driven.
If a write access occurs while E2LAT = 0, then the data on the bus will not be latched.
If a programming cycle is interrupted (by RESET action), the integrity of the data in memory will not be guaranteed.

5.6 DATA EEPROM READ-OUT PROTECTION

The read-out protection is enabled through an op­tion bit (see option byte section).
When this option is selected, the programs and data stored in the EEPROM memory are protected against read-out (including a re-write protection). In Flash devices, when this protection is removed by reprogramming the Option Byte, the entire Pro­gram memory and EEPROM is first automatically erased.
Note: Both Program Memory and data EEPROM are protected using the same option bit.
Figure 10. Data EEPROM Programming Cycle
READ OPERATION NOT POSSIBLE
INTERNAL PROGRAMMING VOLTAGE
ERASE CYCLE WRITE CYCLE
WRITE OF
DATA
LATCHES
t
PROG
READ OPERATION POSSIBLE
LAT
PGM
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1
ST7LITE0xY0, ST7LITESxY0
DATA EEPROM (Cont’d)

5.7 REGISTER DESCRIPTION

EEPROM CONTROL/STATUS REGISTER (EEC­SR)
Read/Write Reset Value: 0000 0000 (00h)
70
000000E2LATE2PGM
Bits 7:2 = Reserved, forced by hardware to 0.
Bit 1 = E2LAT Latch Access Transfer This bit is set by software. It is cleared by hard­ware at the end of the programming cycle. It can only be cleared by software if the E2PGM bit is cleared. 0: Read mode 1: Write mode
Bit 0 = E2PGM Programming control and status This bit is set by software to begin the programming cycle. At the end of the programming cycle, this bit is cleared by hardware. 0: Programming finished or not yet started 1: Programming cycle is in progress
Note: If the E2PGM bit is cleared during the pro­gramming cycle, the memory data is not guaran­teed.
Table 4. DATA EEPROM Register Map and Reset Values
Address
(Hex.)
0030h
Register
Label
EECSR
Reset Value
76543210
000000
E2LAT0E2PGM
0
20/124
1

6 CENTRAL PROCESSING UNIT

ST7LITE0xY0, ST7LITESxY0

6.1 INTRODUCTION

This CPU has a full 8-bit architecture and contains six internal registers allowing efficient 8-bit data manipulation.

6.2 MAIN FEATURES

63 basic instructions
Fast 8-bit by 8-bit multiply
17 main addressing modes
Two 8-bit index registers
16-bit stack pointer
Low power modes
Maskable hardware interrupts
Non-maskable software interrupt

6.3 CPU REGISTERS

The six CPU registers shown in Figure 11 are not present in the memory mapping and are accessed by specific instructions.
Figure 11. CPU Registers
70
RESET VALUE = XXh
70
RESET VALUE = XXh
70
RESET VALUE = XXh
Accumulator (A)
The Accumulator is an 8-bit general purpose reg­ister used to hold operands and the results of the arithmetic and logic calculations and to manipulate data.
Index Registers (X and Y)
In indexed addressing modes, these 8-bit registers are used to create either effective addresses or temporary storage areas for data manipulation. (The Cross-Assembler generates a precede in­struction (PRE) to indicate that the following in­struction refers to the Y register.)
The Y register is not affected by the interrupt auto­matic procedures (not pushed to and popped from the stack).
Program Counter (PC)
The program counter is a 16-bit register containing the address of the next instruction to be executed by the CPU. It is made of two 8-bit registers PCL (Program Counter Low which is the LSB) and PCH (Program Counter High which is the MSB).
ACCUMULATOR
X INDEX REGISTER
Y INDEX REGISTER
15 8
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh
15
RESET VALUE = STACK HIGHER ADDRESS
PCH
RESET VALUE =
7
70
1C11HI NZ 1X11X1XX
70
8
PCL
0
PROGRAM COUNTER
CONDITION CODE REGISTER
STACK POINTER
X = Undefined Value
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1
ST7LITE0xY0, ST7LITESxY0
CPU REGISTERS (Cont’d) CONDITION CODE REGISTER (CC)
Read/Write Reset Value: 111x1xxx
70
111HINZC
The 8-bit Condition Code register contains the in­terrupt mask and four flags representative of the result of the instruction just executed. This register can also be handled by the PUSH and POP in­structions.
These bits can be individually tested and/or con­trolled by specific instructions.
Bit 4 = H Half carry. This bit is set by hardware when a carry occurs be-
tween bits 3 and 4 of the ALU during an ADD or ADC instruction. It is reset by hardware during the same instructions. 0: No half carry has occurred. 1: A half carry has occurred.
This bit is tested using the JRH or JRNH instruc­tion. The H bit is useful in BCD arithmetic subrou­tines.
Bit 3 = I Interrupt mask. This bit is set by hardware when entering in inter-
rupt or by software to disable all interrupts except the TRAP software interrupt. This bit is cleared by software. 0: Interrupts are enabled. 1: Interrupts are disabled.
This bit is controlled by the RIM, SIM and IRET in­structions and is tested by the JRM and JRNM in­structions.
Note: Interrupts requested while I is set are latched and can be processed when I is cleared. By default an interrupt routine is not interruptible
because the I bit is set by hardware at the start of the routine and reset by the IRET instruction at the end of the routine. If the I bit is cleared by software in the interrupt routine, pending interrupts are serviced regardless of the priority level of the cur­rent interrupt routine.
Bit 2 = N Negative. This bit is set and cleared by hardware. It is repre-
sentative of the result sign of the last arithmetic, logical or data manipulation. It is a copy of the 7 bit of the result. 0: The result of the last operation is positive or null. 1: The result of the last operation is negative
(that is, the most significant bit is a logic 1).
This bit is accessed by the JRMI and JRPL instruc­tions.
Bit 1 = Z Zero. This bit is set and cleared by hardware. This bit in-
dicates that the result of the last arithmetic, logical or data manipulation is zero. 0: The result of the last operation is different from
zero.
1: The result of the last operation is zero. This bit is accessed by the JREQ and JRNE test
instructions.
Bit 0 = C Carry/borrow. This bit is set and cleared by hardware and soft-
ware. It indicates an overflow or an underflow has occurred during the last arithmetic operation. 0: No overflow or underflow has occurred. 1: An overflow or underflow has occurred.
This bit is driven by the SCF and RCF instructions and tested by the JRC and JRNC instructions. It is also affected by the “bit test and branch”, shift and rotate instructions.
th
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1
ST7LITE0xY0, ST7LITESxY0
CPU REGISTERS (Cont’d) Stack Pointer (SP)
Read/Write Reset Value: 00 FFh
15 8
00000000
70
1 1 SP5 SP4 SP3 SP2 SP1 SP0
The Stack Pointer is a 16-bit register which is al­ways pointing to the next free location in the stack. It is then decremented after data has been pushed onto the stack and incremented before data is popped from the stack (see Figure 12).
Since the stack is 64 bytes deep, the 10 most sig­nificant bits are forced by hardware. Following an MCU Reset, or after a Reset Stack Pointer instruc­tion (RSP), the Stack Pointer contains its reset val­ue (the SP5 to SP0 bits are set) which is the stack higher address.
The least significant byte of the Stack Pointer (called S) can be directly accessed by a LD in­struction.
Note: When the lower limit is exceeded, the Stack Pointer wraps around to the stack upper limit, with­out indicating the stack overflow. The previously stored information is then overwritten and there­fore lost. The stack also wraps in case of an under­flow.
The stack is used to save the return address dur­ing a subroutine call and the CPU context during an interrupt. The user may also directly manipulate the stack by means of the PUSH and POP instruc­tions. In the case of an interrupt, the PCL is stored at the first location pointed to by the SP. Then the other registers are stored in the next locations as shown in Figure 12.
– When an interrupt is received, the SP is decre-
mented and the context is pushed on the stack.
– On return from interrupt, the SP is incremented
and the context is popped from the stack.
A subroutine call occupies two locations and an in­terrupt five locations in the stack area.
Figure 12. Stack Manipulation Example
@ 00C0h
SP
@ 00FFh
CALL
Subroutine
SP
PCH PCL
Stack Higher Address = 00FFh Stack Lower Address =
Interrupt
event
SP
CC
A X
PCH
PCL
PCH
PCL
00C0h
PUSH Y POP Y IRET
SP
Y
CC
A X
PCH
PCL
PCH
PCL
CC
A X
PCH
PCL PCH PCL
SP
PCH PCL
RET
or RSP
SP
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1
ST7LITE0xY0, ST7LITESxY0

7 SUPPLY, RESET AND CLOCK MANAGEMENT

The device includes a range of utility features for securing the application in critical situations (for example in case of a power brown-out), and re­ducing the number of external components.
Main features
Clock Management
– 1 MHz internal RC oscillator (enabled by op-
tion byte) – External Clock Input (enabled by option byte) – PLL for multiplying the frequency by 4 or 8
(enabled by option byte)
Reset Sequence Manager (RSM)
System Integrity Management (SI)
– Main supply Low voltage detection (LVD) with
reset generation (enabled by option byte) – Auxiliary Voltage detector (AVD) with interrupt
capability for monitoring the main supply (en-
abled by option byte)

7.1 INTERNAL RC OSCILLATOR ADJUSTMENT

The ST7 contains an internal RC oscillator with an accuracy of 1% for a given device, temperature and voltage. It must be calibrated to obtain the fre­quency required in the application. This is done by software writing a calibration value in the RCCR (RC Control Register).
Whenever the microcontroller is reset, the RCCR returns to its default value (FFh), i.e. each time the device is reset, the calibration value must be load­ed in the RCCR. Predefined calibration values are stored in EEPROM for 3.0 and 5V V ages at 25°C, as shown in the following table.
supply volt-
DD
Notes:
– See “ELECTRICAL CHARACTERISTICS” on
page 81. for more information on the frequency and accuracy of the RC oscillator.
– To improve clock stability and frequency accura-
cy, it is recommended to place a decoupling ca­pacitor, typically 100nF, between the V
pins as close as possible to the ST7 device.
V
SS
DD
and
ST7FLITE05/
ST7FLITES5
Address
FFDEh
FFDFh
RCCR Conditions
=5V
V
DD
=25°C
RCCR0
RCCR1
T
A
=1MHz
f
RC
V
DD
=25°C
T
A
=700KHz
f
RC
=3.0V
ST7FLITE09
Address
1000h and FFDEh
1001h and­FFDFh
– These two bytes are systematically programmed
by ST, including on FASTROM devices. Conse­quently, customers intending to us e FASTROM service must not use these two bytes.
– RCCR0 and RCCR1 calibration values will be
erased if the read-out protection bit is reset after it has been set. See “Read out Protection” on page 15.
Caution: If the voltage or temperature conditions change in the application, the frequency may need to be recalibrated.
Refer to application note AN1324 for information on how to calibrate the RC frequency using an ex­ternal reference signal.

7.2 PHASE LOCKED LOOP

The PLL can be used to multiply a 1MHz frequen­cy from the RC oscillator or the external clock by 4 or 8 to obtain f
of 4 or 8 MHz. The PLL is ena-
OSC
bled and the multiplication factor of 4 or 8 is select­ed by 2 option bits.
– The x4 PLL is intended for operation with V
DD
in
the 2.4V to 3.3V range
– The x8 PLL is intended for operation with V
DD
in
the 3.3V to 5.5V range
Refer to Section 15.1 for the option byte descrip­tion.
If the PLL is disabled and the RC oscillator is ena­bled, then f
OSC =
1MHz.
If both the RC oscillator and the PLL are disabled,
is driven by the external clock.
f
OSC
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1
ST7LITE0xY0, ST7LITESxY0
Figure 13. PLL Output Frequency Timing Diagram
LOCKED bit set
4/8 x input
freq.
t
STAB
Bit 1 = MCO Main Clock Out enable This bit is read/write by software and cleared by hardware after a reset. This bit allows to enable the MCO output clock. 0: MCO clock disabled, I/O port free for general
purpose I/O.
1: MCO clock enabled.
Bit 0 = SMS Slow Mode select This bit is read/write by software and cleared by hardware after a reset. This bit selects the input
OSC
or f
clock f 0: Normal mode (f 1: Slow mode (f
/32.
OSC
CPU = fOSC
CPU = fOSC
/32)
RC CONTROL REGISTER (RCCR)
t
STARTUP
Output freq.
t
LOCK
t
Read / Write
When the PLL is started, after reset or wakeup
Reset Value: 1111 1111 (FFh) from Halt mode or AWUFH mode, it outputs the clock after a delay of t
STARTUP
.
70
When the PLL output signal reaches the operating frequency, the LOCKED bit in the SICSCR register is set. Full PLL accuracy (ACC a stabilization time of t
STAB
) is reached after
PLL
(see Figure 13 and
13.3.4 Internal RC Oscillator and PLL)
Refer to section 8.4.4 on page 36 for a description of the LOCKED bit in the SICSR register.
CR7 CR6 CR5 CR4 CR3 CR2 CR1 CR0
Bits 7:0 = CR[7:0] RC Oscillator Frequency Ad-
justment Bits
These bits must be written immediately after reset
to adjust the RC oscillator frequency and to obtain
an accuracy of 1%. The application can store the

7.3 REGISTER DESCRIPTION

MAIN CLOCK CONTROL/STATUS REGISTER (MCCSR)
Read / Write Reset Value: 0000 0000 (00h)
correct value for each voltage range in EEPROM
and write it to this register at start-up.
00h = maximum available frequency
FFh = lowest available frequency
Note: To tune the oscillator, write a series of differ-
ent values in the register until the correct frequen-
70
cy is reached. The fastest method is to use a di-
chotomy starting with 80h.
000000
MCO SMS
Bits 7:2 = Reserved, must be kept cleared.
Table 5. Clock Register Map and Reset Values
Address
(Hex.)
0038h
0039h
Register
Label
MCCSR
Reset Value
RCCR
Reset Value
76543210
000000
CR7
1
CR6
1
CR5
MCO
0
CR4
1
1
CR3
1
CR2
1
CR1
1
SMS
0
CR0
1
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1
ST7LITE0xY0, ST7LITESxY0
SUPPLY, RESET AND CLOCK MANAGEMENT (Cont’d)
Figure 14. Clock Management Block Diagram
CR4CR7 CR0CR1CR2CR3CR6 CR5
Tunable
Oscillator1% RC
Option byte
CLKIN
/2 DIVIDER
LITE TIMER COUNTER
f
OSC
/32 DIVIDER
f
OSC
f
OSC
/32
MCO
7
PLL 1MHz -> 8MHz
PLL 1MHz -> 4MHz
8-BIT
1
0
MCCSR
SMS
0
RCCR
1MHz
8MHz
4MHz
0 to 8 MHz
Option byte
f
LTIMER
(1ms timebase @ 8 MHz f
f
CPU
TO CPU AND PERIPHERALS
(except LITE TIMER)
OSC
f
CPU
f
OSC
)
MCO
26/124
1

7.4 RESET SEQUENCE MANAGER (RSM)

ST7LITE0xY0, ST7LITESxY0

7.4.1 Introduction

The reset sequence manager includes three RE­SET sources as shown in Figure 16:
External RESET source pulse
Internal LVD RESET (Low Voltage Detection)
Internal WATCHDOG RESET
Note: A reset can also be triggered following the detection of an illegal opcode or prebyte code. Re­fer to section 11.2.1 on page 53 for further details.
These sources act on the RESET
pin and it is al-
ways kept low during the delay phase. The RESET service routine vector is fixed at ad-
dresses FFFEh-FFFFh in the ST7 memory map. The basic RESET sequence consists of 3 phases
as shown in Figure 15:
Active Phase depending on the RESET source
256 CPU clock cycle delay
RESET vector fetch
Figure 16.Reset Block Diagram
V
DD
The 256 CPU clock cycle delay allows the oscilla-
tor to stabilise and ensures that recovery has tak-
en place from the Reset state.
The RESET vector fetch phase duration is 2 clock
cycles.
If the PLL is enabled by option byte, it outputs the
clock after an additional delay of t
STARTUP
(see
Figure 13).
Figure 15. RESET Sequence Phases
RESET
Active Phase
INTERNAL RESET
256 CLOCK CYCLES
FETCH
VECTOR
R
ON
RESET
Note 1: See “Illegal Opcode Reset” on page 78. for more details on illegal opcode reset conditions.
FILTER
PULSE
GENERATOR
WATCHDOG RESET ILLEGAL OPCODE RESET
LVD RESET
INTERNAL RESET
1)
27/124
1
ST7LITE0xY0, ST7LITESxY0
RESET SEQUENCE MANAGER (Cont’d)
7.4.2 Asynchronous External RESET
The RESET output with integrated R
pin is both an input and an open-drain
weak pull-up resistor.
ON
pin
This pull-up has no fixed value but varies in ac­cordance with the input voltage. It
can be pulled low by external circuitry to reset the device. See Electrical Characteristic section for more details.
A RESET signal originating from an external source must have a duration of at least t
h(RSTL)in
in order to be recognized (see Figure 17). This de­tection is asynchronous and therefore the MCU can enter reset state even in HALT mode.
The RESET
pin is an asynchronous signal which plays a major role in EMS performance. In a noisy environment, it is recommended to follow the guidelines mentioned in the electrical characteris­tics section.

7.4.3 External Power-On RESET

If the LVD is disabled by option byte, to start up the microcontroller correctly, the user must ensure by means of an external reset circuit that the reset signal is held low until V level specified for the selected f
is over the minimum
DD
frequency.
OSC
Figure 17. RESET Sequences
V
DD
A proper reset signal for a slow rising V
supply
DD
can generally be provided by an external RC net­work connected to the RESET
pin.

7.4.4 Internal Low Voltage Detector (LVD) RESET

Two different RESET sequences caused by the in­ternal LVD circuitry can be distinguished:
Power-On RESET
Voltage Drop RESET
The device RESET pulled low when V V
DD<VIT-
(falling edge) as shown in Figure 17.
The LVD filters spikes on V
pin acts as an output that is
DD<VIT+
(rising edge) or
larger than t
DD
g(VDD)
to
avoid parasitic resets.

7.4.5 Internal Watchdog RESET

The RESET sequence generated by a internal Watchdog counter overflow is shown in Figure 17.
Starting from the Watchdog counter underflow, the device RESET low during at least t
pin acts as an output that is pulled
w(RSTL)out
.
V
IT+(LVD)
V
IT-(LVD)
EXTERNAL RESET SOURCE
RESET PIN
WATCHDOG RESET
RUN
LVD
RESET
ACTIVE PHASE
RUN
t
h(RSTL)in
EXTERNAL
RESET
ACTIVE PHASE
WATCHDOG UNDERFLOW
RUN RUN
INTERNAL RESET (256 T VECTOR FETCH
WATCHDOG
RESET
ACTIVE PHASE
t
w(RSTL)out
CPU
)
28/124
1

8 INTERRUPTS

ST7LITE0xY0, ST7LITESxY0
The ST7 core may be interrupted by one of two dif­ferent methods: Maskable hardware interrupts as listed in the Interrupt Mapping Table and a non­maskable software interrupt (TRAP). The Interrupt processing flowchart is shown in Figure 18. The maskable interrupts must be enabled by clearing the I bit in order to be serviced. However, disabled interrupts may be latched and processed when they are enabled (see external interrupts subsection).
Note: After reset, all interrupts are disabled. When an interrupt has to be serviced: – Normal processing is suspended at the end of
the current instruction execution.
– The PC, X, A and CC registers are saved onto
the stack.
– The I bit of the CC register is set to prevent addi-
tional interrupts.
– The PC is then loaded with the interrupt vector of
the interrupt to service and the first instruction of the interrupt service routine is fetched (refer to the Interrupt Mapping Table for vector address­es).
The interrupt service routine should finish with the IRET instruction which causes the contents of the saved registers to be recovered from the stack.
Note: As a consequence of the IRET instruction, the I bit is cleared and the main program resumes.
Priority Management
By default, a servicing interrupt cannot be inter­rupted because the I bit is set by hardware enter­ing in interrupt routine.
In the case when several interrupts are simultane­ously pending, an hardware priority defines which one will be serviced first (see the Interrupt Map­ping Table).
Interrupts and Low Power Mode
All interrupts allow the processor to leave the WAIT low power mode. Only external and specifi­cally mentioned interrupts allow the processor to leave the HALT low power mode (refer to the “Exit from HALT” column in the Interrupt Mapping Ta­ble).

8.1 NON MASKABLE SOFTWARE INTERRUPT

This interrupt is entered when the TRAP instruc­tion is executed regardless of the state of the I bit. It is serviced according to the flowchart in Figure
18.

8.2 EXTERNAL INTERRUPTS

External interrupt vectors can be loaded into the PC register if the corresponding external interrupt occurred and if the I bit is cleared. These interrupts allow the processor to leave the HALT low power mode.
The external interrupt polarity is selected through the miscellaneous register or interrupt register (if available).
An external interrupt triggered on edge will be latched and the interrupt request automatically cleared upon entering the interrupt service routine.
Caution: The type of sensitivity defined in the Mis­cellaneous or Interrupt register (if available) ap­plies to the ei source. In case of a NANDed source (as described in the I/O ports section), a low level on an I/O pin, configured as input with interrupt, masks the interrupt request even in case of rising­edge sensitivity.

8.3 PERIPHERAL INTERRUPTS

Different peripheral interrupt flags in the status register are able to cause an interrupt when they are active if both:
– The I bit of the CC register is cleared. – The corresponding enable bit is set in the control
register.
If any of these two conditions is false, the interrupt is latched and thus remains pending.
Clearing an interrupt request is done by: – Writing “0” to the corresponding bit in the status
register or
– Access to the status register while the flag is set
followed by a read or write of an associated reg­ister.
Note: The clearing sequence resets the internal latch. A pending interrupt (that is, waiting for being enabled) will therefore be lost if the clear se­quence is executed.
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1
ST7LITE0xY0, ST7LITESxY0
INTERRUPTS (Cont’d)
Figure 18. Interrupt Processing Flowchart
FROM RESET
N
N
INTERRUPT
PENDING?
Y
STACK PC, X, A, CC
SET I BIT
LOAD PC FROM INTERRUPT VECTOR
EXECUTE INSTRUCTION
RESTORE PC, X, A, CC FROM STACK
I BIT SET?
Y
FETCH NEXT INSTRUCTION
N
THIS CLEARS I BIT BY DEFAULT
IRET?
Y
Table 6. Interrupt Mapping
Exit from
HALT
Address
Vector
yes FFFEh-FFFFh
FFF8h-FFF9h
yes
Source
Block
Description
RESET Reset
TRAP Software Interrupt no FFFCh-FFFDh
Register
Label
Priority
Order
Highest
Priority
0 Not used FFFAh-FFFBh 1 ei0 External Interrupt 0
N/A 2 ei1 External Interrupt 1 FFF6h-FFF7h 3 ei2 External Interrupt 2 FFF4h-FFF5h 4 ei3 External Interrupt 3 FFF2h-FFF3h 5 Not used FFF0h-FFF1h 6 Not used FFEEh-FFEFh 7 SI AVD interrupt SICSR no FFECh-FFEDh 8
AT TIMER
9 AT TIMER Overflow Interrupt ATCSR yes FFE8h-FFE9h
10
LITE TIMER
11 LITE TIMER RTC Interrupt LTCSR yes FFE4h-FFE5h 12 SPI SPI Peripheral Interrupts SPICSR yes FFE2h-FFE3h 13 Not used FFE0h-FFE1h
AT TIMER Output Compare Interrupt PWM0CSR no FFEAh-FFEBh
LITE TIMER Input Capture Interrupt LTCSR no FFE6h-FFE7h
Lowest Priority
30/124
1
INTERRUPTS (Cont’d)
ST7LITE0xY0, ST7LITESxY0
EXTERNAL INTERRUPT CONTROL REGISTER (EICR)
Read/Write Reset Value: 0000 0000 (00h)
Notes:
1. These 8 bits can be written only when the I bit in the CC register is set.
2. Changing the sensitivity of a particular external interrupt clears this pending interrupt. This can be
70
used to clear unwanted pending interrupts. Refer to section “External interrupt function” on page 42.
IS31 IS30 IS21 IS20 IS11 IS10 IS01 IS00
Table 7. Interrupt Sensitivity Bits
Bit 7:6 = IS3[1:0] ei3 sensitivity These bits define the interrupt sensitivity for ei3 (Port B0) according to Table 7.
Bit 5:4 = IS2[1:0] ei2 sensitivity These bits define the interrupt sensitivity for ei2 (Port B3) according to Table 7.
ISx1 ISx0 External Interrupt Sensitivity
0 0 Falling edge & low level 0 1 Rising edge only 1 0 Falling edge only 1 1 Rising and falling edge
Bit 3:2 = IS1[1:0] ei1 sensitivity These bits define the interrupt sensitivity for ei1 (Port A7) according to Table 7.
Bit 1:0 = IS0[1:0] ei0 sensitivity These bits define the interrupt sensitivity for ei0 (Port A0) according to Table 7.
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ST7LITE0xY0, ST7LITESxY0

8.4 SYSTEM INTEGRITY MANAGEMENT (SI)

The System Integrity Management block contains the Low voltage Detector (LVD) and Auxiliary Volt­age Detector (AVD) functions. It is managed by the SICSR register.
Note: A reset can also be triggered following the detection of an illegal opcode or prebyte code. Re­fer to section 12.2.1 on page 78 for further details.

8.4.1 Low Voltage Detector (LVD)

The Low Voltage Detector function (LVD) gener­ates a static reset when the V below a V
IT-(LVD)
reference value. This means that
supply voltage is
DD
it secures the power-up as well as the power-down keeping the ST7 in reset.
The V
IT-(LVD)
lower than the V
reference value for a voltage drop is
IT+(LVD)
reference value for power­on in order to avoid a parasitic reset when the MCU starts running and sinks current on the sup­ply (hysteresis).
The LVD Reset circuitry generates a reset when
is below:
V
DD
–V –V
IT+(LVD)
IT-(LVD)
when VDD is rising
when VDD is falling The LVD function is illustrated in Figure 19. The voltage threshold can be configured by option
byte to be low, medium or high. See section 15.1
on page 112.
Provided the minimum V the oscillator frequency) is above V
value (guaranteed for
DD
IT-(LVD)
, the
MCU can only be in two modes:
– under full software control – in static safe reset
In these conditions, secure operation is always en­sured for the application without the need for ex­ternal reset hardware.
During a Low Voltage Detector Reset, the RESET pin is held low, thus permitting the MCU to reset other devices.
Notes: The LVD is an optional function which can be se-
lected by option byte. See section 15.1 on page
112.
It allows the device to be used without any external RESET circuitry.
If the LVD is disabled, an external circuitry must be used to ensure a proper power-on reset.
It is recommended to make sure that the V
DD
sup­ply voltage rises monotonously when the device is exiting from Reset, to ensure the application func­tions properly.
Caution: If an LVD reset occurs after a watchdog reset has occurred, the LVD will take priority and will clear the watchdog flag.
Figure 19. Low Voltage Detector vs Reset
V
DD
V
IT+
(LVD)
V
IT-
(LVD)
RESET
32/124
1
V
hys
Figure 20. Reset and Supply Management Block Diagram
ST7LITE0xY0, ST7LITESxY0
RESET
V
SS
V
DD
RESET SEQUENCE
MANAGER
(RSM)
WATCHDOG
TIMER (WDG)
STATUS FLAG
SYSTEM INTEGRITY MANAGEMENT
SICSR
LOC
0
7
0
00
LOW VOLTAGE
DETECTOR
AUXILIARY VOLTAGE
DETECTOR
KED
(LVD)
(AVD)
RF IE
AVD Interrupt Request
AVDAVDLVD
F
0
33/124
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ST7LITE0xY0, ST7LITESxY0
SYSTEM INTEGRITY MANAGEMENT (Cont’d)

8.4.2 Auxiliary Voltage Detector (AVD)

The Voltage Detector function (AVD) is based on an analog comparison between a V V
IT+(AVD)
ply voltage (V
reference value and the VDD main sup-
). The V
AVD
IT-(AVD)
for falling voltage is lower than the V
IT-(AVD)
reference value
IT+(AVD)
ence value for rising voltage in order to avoid par­asitic detection (hysteresis).
The output of the AVD comparator is directly read­able by the application software through a real time status bit (AVDF) in the SICSR register. This bit is read only.
Caution: The AVD functions only if the LVD is en­abled through the option byte.
and
refer-
8.4.2.1 Monitoring the V
Main Supply
DD
The AVD voltage threshold value is relative to the selected LVD threshold configured by option byte (see section 15.1 on page 112).
If the AVD interrupt is enabled, an interrupt is gen­erated when the voltage crosses the V V
IT-(AVD)
threshold (AVDF bit is set).
IT+(LVD)
or
In the case of a drop in voltage, the AVD interrupt acts as an early warning, allowing software to shut down safely before the LVD resets the microcon­troller. See Figure 21.
The interrupt on the rising edge is used to inform the application that the V
warning state is over
DD
Figure 21. Using the AVD to Monitor V
V
DD
V
IT+(AVD)
V
IT-(AVD)
V
IT+(LVD)
V
IT-(LVD)
AVDF bit
AVD INTERRUPT REQUEST
IF AVDIE bit = 1
LVD RESET
01
INTERRUPT Cleared by
DD
Early Warning Interrupt
(Power has dropped, MCU not not yet in reset)
V
hyst
RESET
reset
01
INTERRUPT Cleared by
hardware
34/124
1
SYSTEM INTEGRITY MANAGEMENT (Cont’d)

8.4.3 Low Power Modes

Mode Description
WAIT
HALT
No effect on SI. AVD interrupts cause the device to exit from Wait mode.
The SICSR register is frozen. The AVD remains active but the AVD inter­rupt cannot be used to exit from Halt mode.
8.4.3.1 Interrupts
The AVD interrupt event generates an interrupt if the corresponding Enable Control Bit (AVDIE) is
ST7LITE0xY0, ST7LITESxY0
set and the interrupt mask in the CC register is re­set (RIM instruction).
Flag
Enable
Control
Bit
Interrupt Event
AVD event AVDF AVDIE Yes No
Event
Exit from Wait
Exit
from
Halt
35/124
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ST7LITE0xY0, ST7LITESxY0
SYSTEM INTEGRITY MANAGEMENT (Cont’d)

8.4.4 Register Description SYSTEM INTEGRITY (SI) CONTROL/STATUS REGISTER (SICSR)

Read/Write Reset Value: 0000 0x00 (0xh)
70
LOCK
0000
LVDRF AVDF AVDIE
ED
Bit 7:4 = Reserved, must be kept cleared.
Bit 3 = LOCKED PLL Locked Flag This bit is set by hardware. It is cleared only by a power-on reset. It is set automatically when the PLL reaches its operating frequency. 0: PLL not locked 1: PLL locked
Bit 2 = LVDRF LVD reset flag This bit indicates that the last Reset was generat­ed by the LVD block. It is set by hardware (LVD re­set) and cleared by software (writing zero). See WDGRF flag description in Section 11.1 for more details. When the LVD is disabled by OPTION BYTE, the LVDRF bit value is undefined.
If the AVDIE bit is set, an interrupt request is gen­erated when the AVDF bit is set. Refer to Figure
21 for additional details
over AVD threshold
0: V
DD
under AVD threshold
1: V
DD
Bit 0 = AVDIE Voltage Detector interrupt enable This bit is set and cleared by software. It enables an interrupt to be generated when the AVDF flag is set. The pending interrupt information is automati­cally cleared when software enters the AVD inter­rupt routine. 0: AVD interrupt disabled 1: AVD interrupt enabled
Application notes
The LVDRF flag is not cleared when another RE­SET type occurs (external or watchdog), the LVDRF flag remains set to keep trace of the origi­nal failure. In this case, a watchdog reset can be detected by software while an external reset can not.
Bit 1 = AVDF Voltage Detector flag This read-only bit is set and cleared by hardware.
Table 8. System Integrity Register Map and Reset Values
Address
(Hex.)
003Ah
Register
Label
SICSR
Reset Value
76543210
0000
LOCKED0LVDRFxAVDF0AVDIE
0
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1

9 POWER SAVING MODES

ST7LITE0xY0, ST7LITESxY0

9.1 INTRODUCTION

To give a large measure of flexibility to the applica­tion in terms of power consumption, four main power saving modes are implemented in the ST7 (see Figure 22): SLOW, WAIT (SLOW WAIT), AC­TIVE HALT and HALT.
After a RESET the normal operating mode is se­lected by default (RUN mode). This mode drives the device (CPU and embedded peripherals) by means of a master clock which is based on the main oscillator frequency (f
OSC
).
From RUN mode, the different power saving modes may be selected by setting the relevant register bits or by calling the specific ST7 software instruction whose action depends on the oscillator status.
Figure 22. Power Saving Mode Transitions
High
RUN
SLOW

9.2 SLOW MODE

This mode has two targets: – To reduce power consumption by decreasing the
internal clock in the device,
– To adapt the internal clock frequency (f
CPU
) to
the available supply voltage.
SLOW mode is controlled by the SMS bit in the MCCSR register which enables or disables Slow mode.
In this mode, the oscillator frequency is divided by
32. The CPU and peripherals are clocked at this lower frequency.
Notes: SLOW-WAIT mode is activated when entering
WAIT mode while the device is already in SLOW mode.
SLOW mode has no effect on the Lite Timer which is already clocked at F
OSC/32
.
Figure 23. SLOW Mode Clock Transition
f
/32 f
f
CPU
OSC
OSC
WAIT
SLOW WAIT
ACTIVE HALT
HALT
Low
POWER CONSUMPTION
f
SMS
OSC
NORMAL RUN MODE
REQUEST
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ST7LITE0xY0, ST7LITESxY0
POWER SAVING MODES (Cont’d)

9.3 WAIT MODE

WAIT mode places the MCU in a low power con­sumption mode by stopping the CPU. This power saving mode is selected by calling the ‘WFI’ instruction. All peripherals remain active. During WAIT mode, the I bit of the CC register is cleared, to enable all interrupts. All other registers and memory remain unchanged. The MCU remains in WAIT mode until an interrupt or RESET occurs, whereupon the Pro­gram Counter branches to the starting address of the interrupt or Reset service routine. The MCU will remain in WAIT mode until a Reset or an Interrupt occurs, causing it to wake up.
Refer to Figure 24.
Figure 24. WAIT Mode Flow-chart
OSCILLATOR
WFI INSTRUCTION
N
INTERRUPT
Y
PERIPHERALS CPU
IBIT
N
RESET
Y
OSCILLATOR PERIPHERALS CPU
IBIT
256 CPU CLOCK CYCLE
DELAY
OSCILLATOR PERIPHERALS CPU
IBIT
ON ON
OFF
0
ON
OFF
ON
0
ON ON ON
X
1)
FETCH RESET VECTOR
OR SERVICE INTERRUPT
Note:
1. Before servicing an interrupt, the CC register is
pushed on the stack. The I bit of the CC register is set during the interrupt routine and cleared when the CC register is popped.
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1
POWER SAVING MODES (Cont’d)
ST7LITE0xY0, ST7LITESxY0

9.4 ACTIVE-HALT AND HALT MODES

ACTIVE-HALT and HALT modes are the two low­est power consumption modes of the MCU. They are both entered by executing the ‘HALT’ instruc­tion. The decision to enter either in ACTIVE-HALT or HALT mode is given by the LTCSR/ATCSR reg­ister status as shown in the following table:.
LTCSR
TBIE bit
ATCSR
OVFIE
0xx0 00xx 0111 1xxx x101
bit
ATCSR CK1 bit
ATCSR
CK0 bit
ACTIVE-HALT mode disabled
ACTIVE-HALT mode enabled
Meaning

9.4.1 ACTIVE-HALT MODE

ACTIVE-HALT mode is the lowest power con­sumption mode of the MCU with a real time clock available. It is entered by executing the ‘HALT’ in­struction when active halt mode is enabled.
The MCU can exit ACTIVE-HALT mode on recep­tion of a Lite Timer / AT Timer interrupt or a RE­SET.
– When exiting ACTIVE-HALT mode by means of
a RESET, a 256 CPU cycle delay occurs. After the start up delay, the CPU resumes operation by fetching the reset vector which woke it up (see
Figure 26).
– When exiting ACTIVE-HALT mode by means of
an interrupt, the CPU immediately resumes oper­ation by servicing the interrupt vector which woke it up (see Figure 26).
When entering ACTIVE-HALT mode, the I bit in the CC register is cleared to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes up immediately.
In ACTIVE-HALT mode, only the main oscillator and the selected timer counter (LT/AT) are running to keep a wake-up time base. All other peripherals are not clocked except those which get their clock supply from another clock generator (such as ex­ternal or auxiliary oscillator).
Caution: As soon as ACTIVE-HALT is enabled, executing a HALT instruction while the Watchdog is active does not generate a RESET if the WDGHALT bit is reset. This means that the device cannot spend more than a defined delay in this power saving mode.
Figure 25. ACTIVE-HALT Timing Overview
ACTIVE
HALTRUN RUN
HALT
INSTRUCTION
[Active Halt Enabled]
256 CPU
CYCLE DELAY
RESET
OR
INTERRUPT
1)
FETCH
VECTOR
Figure 26. ACTIVE-HALT Mode Flow-chart
HALT INSTRUCTION
(Active Halt enabled)
N
INTERRUPT
Y
OSCILLATOR PERIPHERALS CPU
IBIT
N
RESET
Y
3)
OSCILLATOR PERIPHERALS CPU
IBIT
256 CPU CLOCK CYCLE
DELAY
OSCILLATOR PERIPHERALS CPU
IBITS
FETCH RESET VECTOR
OR SERVICE INTERRUPT
2)
2)
ON OFF OFF
0
ON OFF
ON
X
ON
ON
ON
X
4)
4)
Notes:
1. This delay occurs only if the MCU exits ACTIVE-
HALT mode by means of a RESET.
2. Peripherals clocked with an external clock source can still be active.
3. Only the Lite Timer RTC and AT Timer interrupts can exit the MCU from ACTIVE-HALT mode.
4. Before servicing an interrupt, the CC register is pushed on the stack. The I bit of the CC register is set during the interrupt routine and cleared when the CC register is popped.
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ST7LITE0xY0, ST7LITESxY0
POWER SAVING MODES (Cont’d)

9.4.2 HALT MODE

The HALT mode is the lowest power consumption mode of the MCU. It is entered by executing the ‘HALT’ instruction when active halt mode is disa­bled.
The MCU can exit HALT mode on reception of ei­ther a specific interrupt (see Table 6, “Interrupt Mapping,” on page 30) or a RESET. When exiting HALT mode by means of a RESET or an interrupt, the oscillator is immediately turned on and the 256 CPU cycle delay is used to stabilize the oscillator. After the start up delay, the CPU resumes opera­tion by servicing the interrupt or by fetching the re­set vector which woke it up (see Figure 28).
When entering HALT mode, the I bit in the CC reg­ister is forced to 0 to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes immedi­ately.
In HALT mode, the main oscillator is turned off causing all internal processing to be stopped, in­cluding the operation of the on-chip peripherals. All peripherals are not clocked except the ones which get their clock supply from another clock generator (such as an external or auxiliary oscilla­tor).
The compatibility of Watchdog operation with HALT mode is configured by the “WDGHALT” op­tion bit of the option byte. The HALT instruction when executed while the Watchdog system is en­abled, can generate a Watchdog RESET (see sec-
tion 15.1 on page 112 for more details).
Figure 27. HALT Timing Overview
Figure 28. HALT Mode Flow-chart
HALT INSTRUCTION
(Active Halt disabled)
WDGHALT
1
WATCHDOG
RESET
N
INTERRUPT
Y
1)
ENABLE
0
OSCILLATOR PERIPHERALS CPU
IBIT
N
3)
OSCILLATOR PERIPHERALS CPU
IBIT
256 CPU CLOCK CYCLE
OSCILLATOR PERIPHERALS CPU
IBITS
WATCHDOG
RESET
Y
DELAY
DISABLE
OFF
2)
OFF OFF
0
ON OFF
ON
4)
X
ON
ON
ON
4)
X
HALTRUN RUN
HALT
INSTRUCTION
[Active Halt disabled]
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256 CPU CYCLE
DELAY
RESET
OR
INTERRUPT
FETCH
VECTOR
FETCH RESET VECTOR
OR SERVICE INTERRUPT
Notes:
1. WDGHALT is an option bit. See option byte sec-
tion for more details.
2. Peripheral clocked with an external clock source can still be active.
3. Only some specific interrupts can exit the MCU from HALT mode (such as external interrupt). Re­fer to Table 6, “Interrupt Mapping,” on page 30 for more details.
4. Before servicing an interrupt, the CC register is pushed on the stack. The I bit of the CC register is set during the interrupt routine and cleared when the CC register is popped.
5. If the PLL is enabled by option byte, it outputs the clock after a delay of t
STARTUP
(see Figure 13).
POWER SAVING MODES (Cont’d)
9.4.2.1 HALT Mode Recommendations
– Make sure that an external event is available to
wake up the microcontroller from Halt mode.
– When using an external interrupt to wake up the
microcontroller, reinitialize the corresponding I/O as “Input Pull-up with Interrupt” before executing the HALT instruction. The main reason for this is that the I/O may be wrongly configured due to ex­ternal interference or by an unforeseen logical condition.
– For the same reason, reinitialize the level sensi-
tiveness of each external interrupt as a precau­tionary measure.
ST7LITE0xY0, ST7LITESxY0
– The opcode for the HALT instruction is 0x8E. To
avoid an unexpected HALT instruction due to a program counter failure, it is advised to clear all occurrences of the data value 0x8E from memo­ry. For example, avoid defining a constant in ROM with the value 0x8E.
– As the HALT instruction clears the I bit in the CC
register to allow interrupts, the user may choose to clear all pending interrupt bits before execut­ing the HALT instruction. This avoids entering other peripheral interrupt routines after executing the external interrupt routine corresponding to the wake-up event (reset or external interrupt).
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ST7LITE0xY0, ST7LITESxY0

10 I/O PORTS

10.1 INTRODUCTION

The I/O ports offer different functional modes: – transfer of data through digital inputs and outputs
and for specific pins: – external interrupt generation – alternate signal input/output for the on-chip pe-
ripherals.
An I/O port contains up to 8 pins. Each pin can be programmed independently as digital input (with or without interrupt generation) or digital output.

10.2 FUNCTIONAL DESCRIPTION

Each port has 2 main registers: – Data Register (DR) – Data Direction Register (DDR) and one optional register: – Option Register (OR) Each I/O pin may be programmed using the corre-
sponding register bits in the DDR and OR regis­ters: bit X corresponding to pin X of the port. The same correspondence is used for the DR register.
The following description takes into account the OR register, (for specific ports which do not pro­vide this register refer to the I/O Port Implementa­tion section). The generic I/O block diagram is shown in Figure 29

10.2.1 Input Modes

The input configuration is selected by clearing the corresponding DDR register bit.
In this case, reading the DR register returns the digital value applied to the external I/O pin.
Different input modes can be selected by software through the OR register.
Note: Writing the DR register modifies the latch value but does not affect the pin status.
External interrupt function
When an I/O is configured as Input with Interrupt, an event on this I/O can generate an external inter­rupt request to the CPU.
Each pin can independently generate an interrupt request. The interrupt sensitivity is independently programmable using the sensitivity bits in the EICR register.
Each external interrupt vector is linked to a dedi­cated group of I/O port pins (see pinout description and interrupt section). If several input pins are se­lected simultaneously as interrupt source, these
are logically ANDed. For this reason if one of the interrupt pins is tied low, it may mask the others.
External interrupts are hardware interrupts. Fetch­ing the corresponding interrupt vector automatical­ly clears the request latch. Changing the sensitivity of a particular external interrupt clears this pending interrupt. This can be used to clear unwanted pending interrupts.
Spurious interrupts
When enabling/disabling an external interrupt by setting/resetting the related OR register bit, a spu­rious interrupt is generated if the pin level is low and its edge sensitivity includes falling/rising edge. This is due to the edge detector input which is switched to '1' when the external interrupt is disa­bled by the OR register.
To avoid this unwanted interrupt, a "safe" edge sensitivity (rising edge for enabling and falling edge for disabling) has to be selected before changing the OR register bit and configuring the appropriate sensitivity again.
Caution: In case a pin level change occurs during these operations (asynchronous signal input), as interrupts are generated according to the current sensitivity, it is advised to disable all interrupts be­fore and to reenable them after the complete pre­vious sequence in order to avoid an external inter­rupt occurring on the unwanted edge.
This corresponds to the following steps:
1. To enable an external interrupt: – set the interrupt mask with the SIM instruction
(in cases where a pin level change could oc-
cur) – select rising edge – enable the external interrupt through the OR
register – select the desired sensitivity if different from
rising edge – reset the interrupt mask with the RIM instruc-
tion (in cases where a pin level change could
occur)
2. To disable an external interrupt: – set the interrupt mask with the SIM instruction
SIM (in cases where a pin level change could
occur) – select falling edge – disable the external interrupt through the OR
register – select rising edge
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1
ST7LITE0xY0, ST7LITESxY0
– reset the interrupt mask with the RIM instruc-
tion (in cases where a pin level change could occur)
Output Modes
The output configuration is selected by setting the corresponding DDR register bit. In this case, writ­ing the DR register applies this digital value to the I/O pin through the latch. Then reading the DR reg­ister returns the previously stored value.
Two different output modes can be selected by software through the OR register: Output push-pull and open-drain.
DR register value and output pin status:
DR Push-pull Open-drain
0V 1V
SS
DD
Vss
Floating
Note: When switching from input to output mode, the DR register has to be written first to drive the correct level on the pin as soon as the port is con­figured as an output.

10.2.2 Alternate Functions

When an on-chip peripheral is configured to use a pin, the alternate function is automatically select­ed. This alternate function takes priority over the standard I/O programming under the following conditions:
– When the signal is coming from an on-chip pe-
ripheral, the I/O pin is automatically configured in output mode (push-pull or open drain according to the peripheral).
– When the signal is going to an on-chip peripher-
al, the I/O pin must be configured in floating input mode. In this case, the pin state is also digitally
readable by addressing the DR register. Notes: – Input pull-up configuration can cause unexpect-
ed value at the input of the alternate peripheral
input. – When an on-chip peripheral use a pin as input
and output, this pin has to be configured in input
floating mode.
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ST7LITE0xY0, ST7LITESxY0
I/O PORTS (Cont’d)
Figure 29. I/O Port General Block Diagram
REGISTER ACCESS
DATA BUS
DDR SEL
DR
DDR
OR
OR SEL
DR SEL
ALTERNATE OUTPUT
ALTERNATE ENABLE
If implemented
1
1
0
PULL-UP CONDITION
N-BUFFER
V
DD
CMOS SCHMITT TRIGGER
P-BUFFER (see table below)
PULL-UP (see table below)
V
DD
PAD
DIODES (see table below)
ANALOG
INPUT
0
EXTERNAL INTERRUPT SOURCE (eix)
POLARITY SELECTION
Table 9. I/O Port Mode Options
Configuration Mode Pull-Up P-Buffer
Input
Output
Floating with/without Interrupt Off Pull-up with/without Interrupt On Push-pull Open Drain (logic level) Off
Legend: NI - not implemented
Off - implemented not activated On - implemented and activated
FROM OTHER BITS
Off
Off
On
ALTERNATE
Diodes
to V
DD
On On
INPUT
to V
SS
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1
I/O PORTS (Cont’d)
Table 10. I/O Port Configurations
ST7LITE0xY0, ST7LITESxY0
Hardware Configuration
1)
INPUT
2)
OPEN-DRAIN OUTPUT
PAD
PAD
V
DD
R
PU
V
DD
R
PU
PULL-UP CONDITION
FROM
OTHER
PINS
INTERRUPT CONDITION
DR REGISTER ACCESS
DR
REGISTER
ENABLE OUTPUT
W
R
POLARITY
SELECTION
DR REGISTER ACCESS
DR
REGISTER
ALTERNATEALTERNATE
ALTERNATE INPUT
EXTERNAL INTERRUPT SOURCE (eix)
ANALOG INPUT
R/W
DATA B U S
DATA B U S
DR REGISTER ACCESS
DR
REGISTER
ALTERNATEALTERNATE
R/W
DATA B U S
2)
PUSH-PULL OUTPUT
PAD
V
DD
R
PU
ENABLE OUTPUT
Notes:
1. When the I/O port is in input configuration and the associated alternate function is enabled as an output,
reading the DR register will read the alternate function output status.
2. When the I/O port is in output configuration and the associated alternate function is enabled as an input, the alternate function reads the pin status given by the DR register content.
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ST7LITE0xY0, ST7LITESxY0
I/O PORTS (Cont’d) CAUTION: The alternate function must not be ac-
tivated as long as the pin is configured as input with interrupt, in order to avoid generating spurious interrupts.
Analog alternate function
When the pin is used as an ADC input, the I/O must be configured as floating input. The analog multiplexer (controlled by the ADC registers) switches the analog voltage present on the select­ed pin to the common analog rail which is connect­ed to the ADC input.
It is recommended not to change the voltage level or loading on any port pin while conversion is in progress. Furthermore it is recommended not to have clocking pins located close to a selected an­alog pin.
WARNING: The analog input voltage level must be within the limits stated in the absolute maxi­mum ratings.

10.3 UNUSED I/O PINS

Unused I/O pins must be connected to fixed volt­age levels. Refer to Section 13.8.

10.4 LOW POWER MODES

Mode Description
WAIT
HALT
No effect on I/O ports. External interrupts cause the device to exit from WAIT mode.
No effect on I/O ports. External interrupts cause the device to exit from HALT mode.

10.5 INTERRUPTS

The external interrupt event generates an interrupt if the corresponding configuration is selected with DDR and OR registers and the interrupt mask in the CC register is not active (RIM instruction).
Interrupt Event
External interrupt on selected external event
Event
Flag
-
Enable
Control
Bit
DDRx
ORx
Exit
from
Wait
Yes Yes
Exit
from
Halt

10.6 I/O PORT IMPLEMENTATION

The hardware implementation on each I/O port de­pends on the settings in the DDR and OR registers and specific feature of the I/O port such as ADC In­put.
Switching these I/O ports from one state to anoth­er should be done in a sequence that prevents un­wanted side effects. Recommended safe transi­tions are illustrated in Figure 30 Other transitions are potentially risky and should be avoided, since they are likely to present unwanted side-effects such as spurious interrupt generation.
Figure 30. Interrupt I/O Port State Transitions
01
INPUT
floating/pull-up
interrupt
00
INPUT
floating
(reset state)
10
OUTPUT
open-drain
11
OUTPUT push-pull
Table 11. Port Configuration
Port Pin name
PA7 floating
Port A
Port B
46/124
PA6:1 floating pull-up open drain push-pull PA0 floating PB4 floating pull-up open drain push-pull PB3 floating pull-up interrupt open drain push-pull PB2:1 floating pull-up open drain push-pull PB0 floating pull-up interrupt open drain push-pull
1
= DDR, OR
XX
The I/O port register configurations are summa­rised as follows.
Input (DDR=0) Output (DDR=1)
OR = 0 OR = 1 OR = 0 OR = 1
pull-up interrupt
pull-up interrupt
open drain push-pull
open drain push-pull
I/O PORTS (Cont’d)
Table 12. I/O Port Register Map and Reset Values
ST7LITE0xY0, ST7LITESxY0
Address
(Hex.)
0000h
0001h
0002h
0003h
0004h
0005h
Register
Label
PADR
Reset Value
PADDR
Reset Value
PAOR
Reset Value
PBDR
Reset Value
PBDDR
Reset Value
PBOR
Reset Value
76543210
MSB
0000000
MSB
0000000
MSB
0100000
MSB
1110000
MSB
0000000
MSB
0000000
LSB
0
LSB
0
LSB
0
LSB
0
LSB
0
LSB
0
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ST7LITE0xY0, ST7LITESxY0

11 ON-CHIP PERIPHERALS

11.1 LITE TIMER (LT)

11.1.1 Introduction

The Lite Timer can be used for general-purpose timing functions. It is based on a free-running 8-bit upcounter with two software-selectable timebase periods, an 8-bit input capture register and watch­dog function.

11.1.2 Main Features

Realtime Clock
– 8-bit upcounter – 1 ms or 2 ms timebase period (@ 8 MHz f
OSC
– Maskable timebase interrupt
Input Capture
– 8-bit input capture register (LTICR) – Maskable interrupt with wakeup from Halt
Mode capability
Figure 31. Lite Timer Block Diagram
f
LTIMER
f
/32
OSC
8-bit UPCOUNTER
/2
f
LTIMER
Watchdog
– Enabled by hardware or software (configura-
ble by option byte)
– Optional reset on HALT instruction (configura-
ble by option byte)
– Automatically resets the device unless disable
bit is refreshed – Software reset (Forced Watchdog reset) – Watchdog reset status flag
)
To 12-bit AT TImer
f
WDG
1
Timebase 1 or 2 ms
0
(@ 8 MHz f
)
OSC
WATCHDOG
WATCHDOG RESET
LTIC
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1
LTICR
8-bit
INPUT CAPTURE
REGISTER
8
LTCSR
WDG
TBF TBIETBICFICIE
RF
LTTB INTERRUPT REQUEST
LTIC INTERRUPT REQUEST
WDGDWDGE
07
LITE TIMER (Cont’d)

11.1.3 Functional Description

The value of the 8-bit counter cannot be read or written by software. After an MCU reset, it starts incrementing from 0 at a frequency of f
OSC
/32. A counter overflow event occurs when the counter rolls over from F9h to 00h. If f
= 8 MHz, then
OSC
the time period between two counter overflow events is 1 ms. This period can be doubled by set­ting the TB bit in the LTCSR register.
When the timer overflows, the TBF bit is set by hardware and an interrupt request is generated if the TBIE is set. The TBF bit is cleared by software reading the LTCSR register.
11.1.3.1 Watchdog
The watchdog is enabled using the WDGE bit. The normal Watchdog timeout is 2ms (@ = 8 MHz
), after which it then generates a reset.
f
OSC
To prevent this watchdog reset occuring, software must set the WDGD bit. The WDGD bit is cleared by hardware after t
. This means that software
WDG
must write to the WDGD bit at regular intervals to prevent a watchdog reset occurring. Refer to Fig-
ure 32.
If the watchdog is not enabled immediately after reset, the first watchdog timeout will be shorter than 2ms, because this period is counted starting from reset. Moreover, if a 2ms period has already elapsed after the last MCU reset, the watchdog re­set will take place as soon as the WDGE bit is set. For these reasons, it is recommended to enable the Watchdog immediately after reset or else to set the WDGD bit before the WGDE bit so a watchdog reset will not occur for at least 2ms.
A Watchdog reset can be forced at any time by setting the WDGRF bit. To generate a forced
ST7LITE0xY0, ST7LITESxY0
watchdog reset, first watchdog has to be activated by setting the WDGE bit and then the WDGRF bit has to be set.
The WDGRF bit also acts as a flag, indicating that the Watchdog was the source of the reset. It is au­tomatically cleared after it has been read.
Caution: When the WDGRF bit is set, software must clear it, otherwise the next time the watchdog is enabled (by hardware or software), the micro­controller will be immediately reset.
Hardware Watchdog Option
If Hardware Watchdog is selected by option byte, the watchdog is always active and the WDGE bit in the LTCSR is not used.
Refer to the Option Byte description in the "device configuration and ordering information" section.
Using Halt Mode with the Watchdog (option)
If the Watchdog reset on HALT option is not se­lected by option byte, the Halt mode can be used when the watchdog is enabled.
In this case, the HALT instruction stops the oscilla­tor. When the oscillator is stopped, the Lite Timer stops counting and is no longer able to generate a Watchdog reset until the microcontroller receives an external interrupt or a reset.
If an external interrupt is received, the WDG re­starts counting after 256 CPU clocks. If a reset is generated, the Watchdog is disabled (reset state).
If Halt mode with Watchdog is enabled by option byte (No watchdog reset on HALT instruction), it is recommended before executing the HALT instruc­tion to refresh the WDG counter, to avoid an unex­pected WDG reset immediately after waking up the microcontroller.
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ST7LITE0xY0, ST7LITESxY0
LITE TIMER (Cont’d)
Figure 32. Watchdog Timing Diagram
t
WDG
f
WDG
(2ms @ 8 MHz f
HARDWARE CLEARS WDGD BIT
)
OSC
WDGD BIT
INTERNAL WATCHDOG RESET
SOFTWARE SETS
WDGD BIT
WATCHDOG RESET
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LITE TIMER (Cont’d)
ST7LITE0xY0, ST7LITESxY0
Input Capture
The 8-bit input capture register is used to latch the free-running upcounter after a rising or falling edge is detected on the LTIC pin. When an input capture occurs, the ICF bit is set and the LTICR register contains the value of the free-running upcounter. An interrupt is generated if the ICIE bit is set. The ICF bit is cleared by reading the LTICR register.
The LTICR is a read only register and always con­tains the data from the last input capture. Input capture is inhibited if the ICF bit is set.

11.1.4 Low Power Modes

Mode Description
No effect on Lite timer
SLOW
(this peripheral is driven directly by
/32)
f
OSC
WAIT No effect on Lite timer ACTIVE HALT No effect on Lite timer HALT Lite timer stops counting
Figure 33. Input Capture Timing Diagram
4µs
f
(@ 8 MHz f
CPU
OSC
)

11.1.5 Interrupts

Exit
from
Active-
Halt
Yes
Interrupt
Event
Timebase Event
Event
Flag
Enable
Control
Bit
TBF TBIE
Exit
Exit
from
from
Wait
Halt
Yes No
IC Event ICF ICIE No
Note: The TBF and ICF interrupt events are con­nected to separate interrupt vectors (see Inter­rupts chapter).
Timebase and IC events generate an interrupt if the enable bit is set in the LTCSR register and the interrupt mask in the CC register is reset (RIM in­struction).
f
/32
OSC
8-bit COUNTER
LTIC PIN
ICF FLAG
LTICR REGISTER
01h
02h 03h 05h 06h 07h
xxh
04h
04h
CLEARED
BY S/W
READING
LTIC REGISTER
07h
t
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ST7LITE0xY0, ST7LITESxY0
LITE TIMER (Cont’d)

11.1.6 Register Description

LITE TIMER CONTROL/STATUS REGISTER (LTCSR)
Read / Write Reset Value: 0x00 0000 (x0h)
70
ICIE ICF TB TBIE TBF WDGR WDGE WDGD
Bit 7 = ICIE Interrupt Enable This bit is set and cleared by software. 0: Input Capture (IC) interrupt disabled 1: Input Capture (IC) interrupt enabled
Bit 6 = ICF Input Capture Flag This bit is set by hardware and cleared by software by reading the LTICR register. Writing to this bit does not change the bit value. 0: No input capture 1: An input capture has occurred
Note: After an MCU reset, software must initialise the ICF bit by reading the LTICR register
0: No counter overflow 1: A counter overflow has occurred
Bit 2 = WDGRF Force Reset/ Reset Status Flag This bit is used in two ways: it is set by software to force a watchdog reset. It is set by hardware when a watchdog reset occurs and cleared by hardware or by software. It is cleared by hardware only when an LVD reset occurs. It can be cleared by software after a read access to the LTCSR register. 0: No watchdog reset occurred. 1: Force a watchdog reset (write), or, a watchdog
reset occurred (read).
Bit 1 = WDGE Watchdog Enable This bit is set and cleared by software. 0: Watchdog disabled 1: Watchdog enabled
Bit 0 = WDGD Watchdog Reset Delay This bit is set by software. It is cleared by hard­ware at the end of each t
WDG
0: Watchdog reset not delayed 1: Watchdog reset delayed
period.
Bit 5 = TB Timebase period selection This bit is set and cleared by software. 0: Timebase period = t 1: Timebase period = t
* 8000 (1ms @ 8 MHz)
OSC
* 16000 (2ms @ 8
OSC
MHz)
Bit 4 = TBIE Timebase Interrupt enable This bit is set and cleared by software. 0: Timebase (TB) interrupt disabled 1: Timebase (TB) interrupt enabled
Bit 3 = TBF Timebase Interrupt Flag This bit is set by hardware and cleared by software reading the LTCSR register. Writing to this bit has no effect.
Table 13. Lite Timer Register Map and Reset Values
Address
(Hex.)
0B
0C
Register
Label
LTCSR
Reset Value
LTICR
Reset Value
76543210
ICIE
0
ICR7
0
ICF
x
ICR6
0
TB
0
ICR5
0
LITE TIMER INPUT CAPTURE REGISTER (LTICR)
Read only Reset Value: 0000 0000 (00h)
70
ICR7 ICR6 ICR5 ICR4 ICR3 ICR2 ICR1 ICR0
Bit 7:0 = ICR[7:0] Input Capture Value These bits are read by software and cleared by hardware after a reset. If the ICF bit in the LTCSR is cleared, the value of the 8-bit up-counter will be captured when a rising or falling edge occurs on the LTIC pin.
TBIE
0
ICR4
0
TBF0WDGRF0WDGE0WDGD
0
ICR3
0
ICR2
0
ICR1
0
ICR0
0
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11.2 12-BIT AUTORELOAD TIMER (AT)

ST7LITE0xY0, ST7LITESxY0

11.2.1 Introduction

The 12-bit Autoreload Timer can be used for gen­eral-purpose timing functions. It is based on a free­running 12-bit upcounter with a PWM output chan­nel.

11.2.2 Main Features

12-bit upcounter with 12-bit autoreload register
(ATR)
Maskable overflow interrupt
Figure 34. Block Diagram
ATCSR
70
f
LTIMER
(1 ms timebase @ 8MHz)
f
CPU
f
COUNTER
CNTR
ATR
PWM signal generator
Frequency range 2KHz-4MHz (@ 8 MHz f
– Programmable duty-cycle – Polarity control – Maskable Compare interrupt
Output Compare Function
OVF INTERRUPT REQUEST
CMPIEOVFIEOVFCK0CK1000
CMP INTERRUPT
CMPF0
12-BIT UPCOUNTER
REQUEST
Update on OVF Event
12-BIT AUTORELOAD VALUE
CPU
)
DCR0H
Preload
DCR0L
Preload
on OVF Event IF OE0=1
12-BIT DUTY CYCLE VALUE (shadow)
OE0 bit
0
1
CMPF0 bit
COMP-
PARE
f
PWM
PWM GENERATION
OP0 bit
POL­ARITY
OE0 bit
PWM0
OUTPUT CONTROL
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ST7LITE0xY0, ST7LITESxY0
12-BIT AUTORELOAD TIMER (Cont’d)

11.2.3 Functional Description PWM Mode

This mode allows a Pulse Width Modulated sig­nals to be generated on the PWM0 output pin with minimum core processing overhead. The PWM0 output signal can be enabled or disabled using the OE0 bit in the PWMCR register. When this bit is set the PWM I/O pin is configured as output push­pull alternate function.
Note: CMPF0 is available in PWM mode (see PWM0CSR description on page 57).
PWM Frequency and Duty Cycle
The PWM signal frequency (f the counter period and the ATR register value.
f
PWM
= f
COUNTER
/ (4096 - ATR)
Following the above formula, if f maximum value of f
is 4 Mhz (ATR register
PWM
value = 4094), and the minimum value is 2 kHz (ATR register value = 0).
Note: The maximum value of ATR is 4094 be­cause it must be lower than the DCR value which must be 4095 in this case.
At reset, the counter starts counting from 0. Software must write the duty cycle value in the
DCR0H and DCR0L preload registers. The DCR0H register must be written first. See caution below.
) is controlled by
PWM
is 8 MHz, the
CPU
When a upcounter overflow occurs (OVF event), the ATR value is loaded in the upcounter, the preloaded Duty cycle value is transferred to the Duty Cycle register and the PWM0 signal is set to a high level. When the upcounter matches the DCRx value the PWM0 signals is set to a low level. To obtain a signal on the PWM0 pin, the contents of the DCR0 register must be greater than the con­tents of the ATR register.
The polarity bit can be used to invert the output signal.
The maximum available resolution for the PWM0 duty cycle is:
Resolution = 1 / (4096 - ATR)
Note: To get the maximum resolution (1/4096), the ATR register must be 0. With this maximum reso­lution and assuming that DCR=ATR, a 0% or 100% duty cycle can be obtained by changing the polarity .
Caution: As soon as the DCR0H is written, the compare function is disabled and will start only when the DCR0L value is written. If the DCR0H write occurs just before the compare event, the signal on the PWM output may not be set to a low level. In this case, the DCRx register should be up­dated just after an OVF event. If the DCR and ATR values are close, then the DCRx register shouldbe updated just before an OVF event, in order not to miss a compare event and to have the right signal applied on the PWM output.
Figure 35. PWM Function
4095
DUTY CYCLE
REGISTER
(DCR0)
AUTO-RELOAD
COUNTER
REGISTER
(ATR)
000
WITH OE0=1 AND OP0=0
WITH OE0=1 AND OP0=1
PWM0 OUTPUT
54/124
t
1
12-BIT AUTORELOAD TIMER (Cont’d)
Figure 36. PWM Signal Example
f
COUNTER
ST7LITE0xY0, ST7LITESxY0
ATR= FFDh
PWM0 OUTPUT
AND OP0=0
WITH OE0=1
COUNTER
DCR0=FFEh
FFDh FFEh FFFh FFDh FFEh FFFh FFDh FFEh
Output Compare Mode
To use this function, the OE bit must be 0, other­wise the compare is done with the shadow register instead of the DCRx register. Software must then write a 12-bit value in the DCR0H and DCR0L reg­isters. This value will be loaded immediately (with­out waiting for an OVF event).
The DCR0H must be written first, the output com­pare function starts only when the DCR0L value is written.
When the 12-bit upcounter (CNTR) reaches the value stored in the DCR0H and DCR0L registers, the CMPF0 bit in the PWM0CSR register is set and an interrupt request is generated if the CMPIE bit is set.
Note: The output compare function is only availa­ble for DCRx values other than 0 (reset value).
Caution: At each OVF event, the DCRx value is written in a shadow register, even if the DCR0L value has not yet been written (in this case, the shadow register will contain the new DCR0H value and the old DCR0L value), then:
– If OE=1 (PWM mode): the compare is done be-
tween the timer counter and the shadow register (and not DCRx)
– if OE=0 (OCMP mode): the compare is done be-
tween the timer counter and DCRx. There is no PWM signal.
t
The compare between DCRx or the shadow regis­ter and the timer counter is locked until DCR0L is written.

11.2.4 Low Power Modes

Mode Description
SLOW
The input frequency is divided by 32
WAIT No effect on AT timer
ACTIVE-HALT
AT timer halted except if CK0=1, CK1=0 and OVFIE=1
HALT AT timer halted

11.2.5 Interrupts

Interrupt
Event
Overflow Event
CMP Event CMPFx CMPIE Yes No No
Event
1)
Enable
Control
Flag
OVF OVFIE Yes No Yes
Bit
Exit from Wait
Exit
from
Halt
Exit
from
Active-
Halt
2)
Notes:
1. The interrupt events are connected to separate
interrupt vectors (see Interrupts chapter). They generate an interrupt if the enable bit is set in the ATCSR register and the interrupt mask in the CC register is reset (RIM instruction).
2. only if CK0=1and CK1=0
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1
ST7LITE0xY0, ST7LITESxY0
12-BIT AUTORELOAD TIMER (Cont’d)

11.2.6 Register Description

TIMER CONTROL STATUS REGISTER (ATC­SR)
Read / Write Reset Value: 0000 0000 (00h)
hardware after a reset. It allows to mask the inter­rupt generation when CMPF bit is set. 0: CMPF interrupt disabled 1: CMPF interrupt enabled
70
0 0 0 CK1 CK0 OVF OVFIE CMPIE
Bit 7:5 = Reserved, must be kept cleared.
COUNTER REGISTER HIGH (CNTRH)
Read only Reset Value: 0000 0000 (00h)
15 8
0 0 0 0 CN11 CN10 CN9 CN8
Bit 4:3 = CK[1:0] Counter Clock Selection. These bits are set and cleared by software and cleared by hardware after a reset. They select the clock frequency of the counter.
COUNTER REGISTER LOW (CNTRL)
Read only Reset Value: 0000 0000 (00h)
Counter Clock Selection CK1 CK0
OFF 0 0
(1 ms timebase @ 8 MHz) 0 1
f
LTIMER
f
CPU
Reserved 1 1
10
70
CN7 CN6 CN5 CN4 CN3 CN2 CN1 CN0
Bits 15:12 = Reserved, must be kept cleared.
Bits 11:0 = CNTR[11:0] Counter Value. Bit 2 = OVF Overflow Flag. This bit is set by hardware and cleared by software by reading the ATCSR register. It indicates the transition of the counter from FFFh to ATR value. 0: No counter overflow occurred 1: Counter overflow occurred
Caution:
When set, the OVF bit stays high for 1 f
COUNTER
cycle, (up to 1ms depending on the clock selec­tion).
This 12-bit register is read by software and cleared
by hardware after a reset. The counter is incre-
mented continuously as soon as a counter clock is
selected. To obtain the 12-bit value, software
should read the counter value in two consecutive
read operations. The CNTRH register can be in-
cremented between the two reads, and in order to
be accurate when f
TIMER=fCPU
should take this into account when CNTRL and
CNTRH are read. If CNTRL is close to its highest
value, CNTRH could be incremented before it is
read.
, the software
Bit 1 = OVFIE Overflow Interrupt Enable. This bit is read/write by software and cleared by hardware after a reset. 0: OVF interrupt disabled 1: OVF interrupt enabled
Bit 0 = CMPIE Compare Interrupt Enable. This bit is read/write by software and clear by
56/124
1
When a counter overflow occurs, the counter re-
starts from the value specified in the ATR register.
12-BIT AUTORELOAD TIMER (Cont’d) AUTO RELOAD REGISTER (ATRH)
Read / Write Reset Value: 0000 0000 (00h)
ST7LITE0xY0, ST7LITESxY0
PWM0 DUTY CYCLE REGISTER LOW (DCR0L)
Read / Write
Reset Value: 0000 0000 (00h)
15 8
0 0 0 0 ATR11 ATR10 ATR9 ATR8
AUTO RELOAD REGISTER (ATRL)
70
DCR7 DCR6 DCR5 DCR4 DCR3 DCR2 DCR1 DCR0
Bits 15:12 = Reserved, must be kept cleared. Read / Write Reset Value: 0000 0000 (00h)
70
Bits 11:0 = DCR[11:0] PWMx Duty Cycle Value
This 12-bit value is written by software. The high
register must be written first.
ATR7 ATR6 ATR5 ATR4 ATR3 ATR2 ATR1 ATR0
In PWM mode (OE0=1 in the PWMCR register)
the DCR[11:0] bits define the duty cycle of the Bits 15:12 = Reserved, must be kept cleared.
PWM0 output signal (see Figure 35). In Output
Compare mode, (OE0=0 in the PWMCR register)
they define the value to be compared with the 12­Bits 11:0 = ATR[11:0] Autoreload Register.
bit upcounter value. This is a 12-bit register which is written by soft-
ware. The ATR register value is automatically loaded into the upcounter when an overflow oc­curs. The register value is used to set the PWM frequency.
PWM0 CONTROL/STATUS REGISTER
(PWM0CSR)
Read / Write
Reset Value: 0000 0000 (00h)
PWM0 DUTY CYCLE REGISTER HIGH (DCR0H)
70
Read / Write Reset Value: 0000 0000 (00h)
000000OP0CMPF0
15 8
0 0 0 0 DCR11 DCR10 DCR9 DCR8
Bit 7:2= Reserved, must be kept cleared.
Bit 1 = OP0 PWM0 Output Polarity.
This bit is read/write by software and cleared by
hardware after a reset. This bit selects the polarity
of the PWM0 signal.
0: The PWM0 signal is not inverted.
1: The PWM0 signal is inverted.
Bit 0 = CMPF0 PWM0 Compare Flag.
This bit is set by hardware and cleared by software
by reading the PWM0CSR register. It indicates
that the upcounter value matches the DCR0 regis-
ter value.
0: Upcounter value does not match DCR value.
1: Upcounter value matches DCR value.
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1
ST7LITE0xY0, ST7LITESxY0
12-BIT AUTORELOAD TIMER (Cont’d)
PWM OUTPUT CONTROL REGISTER (PWMCR)
Bits 7:1 = Reserved, must be kept cleared. Read/Write Reset Value: 0000 0000 (00h)
70
Bit 0 = OE0 PWM0 Output enable.
This bit is set and cleared by software.
0: PWM0 output Alternate Function disabled (I/O
0000000OE0
pin free for general purpose I/O)
1: PWM0 output enabled
Table 14. Register Map and Reset Values
Address
(Hex.)
0D
0E
0F
10
11
12
13
17
18
Register
Label
ATCSR
Reset Value
CNTRH
Reset Value
CNTRL
Reset Value
ATRH
Reset Value
ATRL
Reset Value
PWMCR
Reset Value
PWM0CSR
Reset Value
DCR0H
Reset Value
DCR0L
Reset Value
76543210
000
0000
CN7
0
0000
ATR7
0
0000000
000000
0000
DCR7
0
CN6
0
ATR6
0
DCR60DCR5
CN5
0
ATR5
0
0
CK1
0
CN4
0
ATR4
0
DCR4
0
CK0
0
CN11
0
CN3
0
ATR110ATR100ATR9
ATR3
0
DCR11
0
DCR30DCR2
OVF
0
CN10
0
CN2
0
ATR2
0
DCR100DCR9
0
OVFIE0CMPIE
0
CN9
0
CN1
0
0
ATR1
0
OP
0
0
DCR1
0
CN8
0
CN0
0
ATR8
0
ATR0
0
OE0
0
CMPF0
0
DCR8
0
DCR0
0
58/124
1

11.3 SERIAL PERIPHERAL INTERFACE (SPI)

ST7LITE0xY0, ST7LITESxY0

11.3.1 Introduction

The Serial Peripheral Interface (SPI) allows full­duplex, synchronous, serial communication with external devices. An SPI system may consist of a master and one or more slaves however the SPI interface can not be a master in a multi-master system.

11.3.2 Main Features

Full duplex synchronous transfers (on 3 lines)
Simplex synchronous transfers (on 2 lines)
Master or slave operation
Six master mode frequencies (f
f
SS Management by software or hardware
Programmable clock polarity and phase
End of transfer interrupt flag
Write collision, Master Mode Fault and Overrun
/2 max. slave mode frequency (see note)
CPU
CPU
/4 max.)
flags
Note: In slave mode, continuous transmission is not possible at maximum frequency due to the
Figure 37. Serial Peripheral Interface Block Diagram
Data/Address Bus
software overhead for clearing status flags and to
initiate the next transmission sequence.

11.3.3 General Description

Figure 37 shows the serial peripheral interface
(SPI) block diagram. There are 3 registers:
– SPI Control Register (SPICR) – SPI Control/Status Register (SPICSR) – SPI Data Register (SPIDR)
The SPI is connected to external devices through
3 pins:
– MISO: Master In / Slave Out data – MOSI: Master Out / Slave In data – SCK: Serial Clock out by SPI masters and in-
put by SPI slaves
: Slave select:
–SS
This input signal acts as a ‘chip select’ to let the SPI master communicate with slaves indi­vidually and to avoid contention on the data lines. Slave SS
inputs can be driven by stand-
ard I/O ports on the master MCU.
MOSI
MISO
SCK
SS
SOD
bit
SPIDR
Read Buffer
8-Bit Shift Register
SERIAL CLOCK
Read
Write
MASTER
CONTROL
GENERATOR
Interrupt
request
SPIF WCOL MODF
SPIE SPE
OVR SSISSMSOD
SPI
STATE
CONTROL
MSTR
SPR2
0
CPOL
SS
CPHA
SPICSR
1
0
SPICR
SPR1
07
07
SPR0
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ST7LITE0xY0, ST7LITESxY0
SERIAL PERIPHERAL INTERFACE (Cont’d)
11.3.3.1 Functional Description
A basic example of interconnections between a single master and a single slave is illustrated in
Figure 38.
The MOSI pins are connected together and the MISO pins are connected together. In this way data is transferred serially between master and slave (most significant bit first).
The communication is always initiated by the mas­ter. When the master device transmits data to a slave device via MOSI pin, the slave device re-
Figure 38. Single Master/ Single Slave Application
sponds by sending data to the master device via
the MISO pin. This implies full duplex communica-
tion with both data out and data in synchronized
with the same clock signal (which is provided by
the master device via the SCK pin).
To use a single data line, the MISO and MOSI pins
must be connected at each node (in this case only
simplex communication is possible).
Four possible data/clock timing relationships may
be chosen (see Figure 41) but master and slave
must be programmed with the same timing mode.
MASTER
MSBit LSBit MSBit LSBit
8-BIT SHIFT REGISTER
SPI
CLOCK
GENERATOR
MISO
MOSI
SCK
SS
+5V
MISO
MOSI
SCK
SS
8-BIT SHIFT REGISTER
SLAVE
Not used if SS is managed by software
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1
SERIAL PERIPHERAL INTERFACE (Cont’d)
11.3.3.2 Slave Select Management
As an alternative to using the SS
pin to control the Slave Select signal, the application can choose to manage the Slave Select signal by software. This is configured by the SSM bit in the SPICSR regis­ter (see Figure 40)
In software management, the external SS
pin is free for other application uses and the internal SS signal level is driven by writing to the SSI bit in the SPICSR register.
In Master mode:
–SS
internal must be held high continuously
ST7LITE0xY0, ST7LITESxY0
In Slave Mode:
There are two cases depending on the data/clock timing relationship (see Figure 39):
If CPHA=1 (data latched on 2nd clock edge):
–SS
internal must be held low during the entire transmission. This implies that in single slave applications the SS V
, or made free for standard I/O by manag-
SS
ing the SS
function by software (SSM= 1 and
SSI=0 in the in the SPICSR register)
If CPHA=0 (data latched on 1st clock edge):
–SS
internal must be held low during byte transmission and pulled high between each byte to allow the slave to write to the shift reg­ister. If SS
is not pulled high, a Write Collision error will occur when the slave writes to the shift register (see Section 11.3.5.3).
pin either can be tied to
Figure 39. Generic SS
MOSI/MISO
Master SS
Slave SS
(if CPHA=0)
Slave SS
(if CPHA=1)
Timing Diagram
Byte 1 Byte 2
Figure 40. Hardware/Software Slave Select Management
SSM bit
external pin
SS
SSI bit
1
0
SS internal
Byte 3
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ST7LITE0xY0, ST7LITESxY0
SERIAL PERIPHERAL INTERFACE (Cont’d)
11.3.3.3 Master Mode Operation
In master mode, the serial clock is output on the SCK pin. The clock frequency, polarity and phase are configured by software (refer to the description of the SPICSR register).
Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL=1 or pulling down SCK if CPOL=0).
How to operate the SPI in master mode
To operate the SPI in master mode, perform the following steps in order:
1. Write to the SPICR register: – Select the clock frequency by configuring the
SPR[2:0] bits.
– Select the clock polarity and clock phase by
configuring the CPOL and CPHA bits. Figure
41 shows the four possible configurations.
Note: The slave must have the same CPOL and CPHA settings as the master.
2. Write to the SPICSR register: – Either set the SSM bit and set the SSI bit or
clear the SSM bit and tie the SS the complete byte transmit sequence.
3. Write to the SPICR register: – Set the MSTR and SPE bits
Note: MSTR and SPE bits remain set only if SS
is high.
Important note: if the SPICSR register is not writ­ten first, the SPICR register setting (MSTR bit) may be not taken into account.
The transmit sequence begins when software writes a byte in the SPIDR register.
11.3.3.4 Master Mode Transmit Sequence
When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MOSI pin most sig­nificant bit first.
When data transfer is complete:
– The SPIF bit is set by hardware – An interrupt request is generated if the SPIE
bit is set and the interrupt mask in the CCR register is cleared.
Clearing the SPIF bit is performed by the following software sequence:
1. An access to the SPICSR register while the SPIF bit is set
2. A read to the SPIDR register.
pin high for
Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR reg­ister is read.
11.3.3.5 Slave Mode Operation
In slave mode, the serial clock is received on the SCK pin from the master device.
To operate the SPI in slave mode:
1. Write to the SPICSR register to perform the fol­lowing actions:
– Select the clock polarity and clock phase by
configuring the CPOL and CPHA bits (see
Figure 41).
Note: The slave must have the same CPOL and CPHA settings as the master.
– Manage the SS
11.3.3.2 and Figure 39. If CPHA=1 SS
be held low continuously. If CPHA=0 SS be held low during byte transmission and pulled up between each byte to let the slave write in the shift register.
2. Write to the SPICR register to clear the MSTR bit and set the SPE bit to enable the SPI I/O functions.
11.3.3.6 Slave Mode Transmit Sequence
When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MISO pin most sig­nificant bit first.
The transmit sequence begins when the slave de­vice receives the clock signal and the most signifi­cant bit of the data on its MOSI pin.
When data transfer is complete:
– The SPIF bit is set by hardware – An interrupt request is generated if SPIE bit is
set and interrupt mask in the CCR register is cleared.
Clearing the SPIF bit is performed by the following software sequence:
1. An access to the SPICSR register while the SPIF bit is set.
2. A write or a read to the SPIDR register.
Notes: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR reg­ister is read.
The SPIF bit can be cleared during a second transmission; however, it must be cleared before the second SPIF bit in order to prevent an Overrun condition (see Section 11.3.5.2).
pin as described in Section
must
must
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1
SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.4 Clock Phase and Clock Polarity

Four possible timing relationships may be chosen by software, using the CPOL and CPHA bits (See
Figure 41).
Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL=1 or pulling down SCK if CPOL=0).
The combination of the CPOL clock polarity and CPHA (clock phase) bits selects the data capture clock edge
Figure 41. Data Clock Timing Diagram
SCK (CPOL = 1)
SCK (CPOL = 0)
ST7LITE0xY0, ST7LITESxY0
Figure 41, shows an SPI transfer with the four
combinations of the CPHA and CPOL bits. The di­agram may be interpreted as a master or slave timing diagram where the SCK pin, the MISO pin, the MOSI pin are directly connected between the master and the slave device.
Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by re­setting the SPE bit.
CPHA =1
MISO
(from master)
MOSI
(from slave)
SS
(to slave)
CAPTURE STROBE
SCK (CPOL = 1)
SCK (CPOL = 0)
MISO
(from master)
MOSI
(from slave)
SS
(to slave)
CAPTURE STROBE
MSBit Bit 6 Bit 5
MSBit Bit 6 Bit 5
MSBit Bit 6 Bit 5
MSBit Bit 6 Bit 5
Bit 4 Bit3 Bit 2 Bit 1 LSBit
Bit 4 Bit3Bit 2Bit 1LSBit
CPHA =0
Bit 4 Bit3 Bit 2 Bit 1 LSBit
Bit 4 Bit3 Bit 2 Bit 1 LSBit
Note:
This figure should not be used as a replacement for parametric information.
Refer to the Electrical Characteristics chapter.
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ST7LITE0xY0, ST7LITESxY0
SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.5 Error Flags

11.3.5.1 Master Mode Fault (MODF)
Master mode fault occurs when the master device has its SS
When a Master mode fault occurs:
– The MODF bit is set and an SPI interrupt re-
– The SPE bit is reset. This blocks all output
– The MSTR bit is reset, thus forcing the device
Clearing the MODF bit is done through a software sequence:
1. A read access to the SPICSR register while the
2. A write to the SPICR register. Notes: To avoid any conflicts in an application
with multiple slaves, the SS high during the MODF bit clearing sequence. The SPE and MSTR bits may be restored to their orig­inal state during or after this clearing sequence.
Hardware does not allow the user to set the SPE and MSTR bits while the MODF bit is set except in the MODF bit clearing sequence.
11.3.5.2 Overrun Condition (OVR)
An overrun condition occurs, when the master de­vice has sent a data byte and the slave device has
pin pulled low.
quest is generated if the SPIE bit is set.
from the device and disables the SPI periph­eral.
into slave mode.
MODF bit is set.
pin must be pulled
not cleared the SPIF bit issued from the previously transmitted byte.
When an Overrun occurs: – The OVR bit is set and an interrupt request is
generated if the SPIE bit is set.
In this case, the receiver buffer contains the byte sent after the SPIF bit was last cleared. A read to the SPIDR register returns this byte. All other bytes are lost.
The OVR bit is cleared by reading the SPICSR register.
11.3.5.3 Write Collision Error (WCOL)
A write collision occurs when the software tries to write to the SPIDR register while a data transfer is taking place with an external device. When this happens, the transfer continues uninterrupted; and the software write will be unsuccessful.
Write collisions can occur both in master and slave mode. See also Section 11.3.3.2 Slave Select
Management.
Note: a "read collision" will never occur since the received data byte is placed in a buffer in which access is always synchronous with the MCU oper­ation.
The WCOL bit in the SPICSR register is set if a write collision occurs.
No SPI interrupt is generated when the WCOL bit is set (the WCOL bit is a status flag only).
Clearing the WCOL bit is done through a software sequence (see Figure 42).
Figure 42. Clearing the WCOL bit (Write Collision Flag) Software Sequence
Clearing sequence after SPIF = 1 (end of a data byte transfer)
1st Step
2nd Step
Read SPICSR
Read SPIDR
RESULT
SPIF =0 WCOL=0
Clearing sequence before SPIF = 1 (during a data byte transfer)
1st Step
2nd Step
64/124
Read SPICSR
Read SPIDR
RESULT
WCOL=0
Note: Writing to the SPIDR regis­ter instead of reading it does not reset the WCOL bit
1
SERIAL PERIPHERAL INTERFACE (Cont’d)
11.3.5.4 Single Master Systems
A typical single master system may be configured, using an MCU as the master and four MCUs as slaves (see Figure 43).
The master device selects the individual slave de­vices by using four pins of a parallel port to control the four SS
The SS master device ports will be forced to be inputs at that time, thus disabling the slave devices.
Figure 43. Single Master / Multiple Slave Configuration
pins of the slave devices.
pins are pulled high during reset since the
Note: To prevent a bus conflict on the MISO line the master allows only one active slave device during a transmission.
For more security, the slave device may respond to the master with the received data byte. Then the master will receive the previous byte back from the slave device if all MISO and MOSI pins are con­nected and the slave has not written to its SPIDR register.
Other transmission security methods can use ports for handshake lines or data bytes with com­mand fields.
ST7LITE0xY0, ST7LITESxY0
5V
SCK
MCU
MOSI
MOSI
SCK
Master MCU
SS
SS SS
SCK
Slave
MOSI MOSI MOSIMISO MISO MISOMISO
MISO
Ports
Slave
MCU
SS
SCK SCK
Slave
MCU
SS
Slave MCU
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ST7LITE0xY0, ST7LITESxY0
SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.6 Low Power Modes

Mode Description
WAIT
HALT
11.3.6.1 Using the SPI to wakeup the MCU from Halt mode
In slave configuration, the SPI is able to wakeup the ST7 device from HALT mode through a SPIF interrupt. The data received is subsequently read from the SPIDR register when the software is run­ning (interrupt vector fetch). If multiple data trans­fers have been performed before software clears the SPIF bit, then the OVR bit is set by hardware.
Note: When waking up from Halt mode, if the SPI remains in Slave mode, it is recommended to per­form an extra communications cycle to bring the SPI from Halt mode state to normal state. If the
No effect on SPI. SPI interrupt events cause the device to exit from WAIT mode.
SPI registers are frozen. In HALT mode, the SPI is inactive. SPI oper­ation resumes when the MCU is woken up by an interrupt with “exit from HALT mode” ca­pability. The data received is subsequently read from the SPIDR register when the soft­ware is running (interrupt vector fetching). If several data are received before the wake­up event, then an overrun error is generated. This error can be detected after the fetch of the interrupt routine that woke up the device.
SPI exits from Slave mode, it returns to normal state immediately.
Caution: The SPI can wake up the ST7 from Halt mode only if the Slave Select signal (external SS pin or the SSI bit in the SPICSR register) is low when the ST7 enters Halt mode. So if Slave selec­tion is configured as external (see Section
11.3.3.2), make sure the master drives a low level
on the SS
pin when the slave enters Halt mode.

11.3.7 Interrupts

Interrupt Event
SPI End of Trans­fer Event
Master Mode Fault Event
Overrun Error OVR Yes No
Event
Flag
SPIF
MODF Yes No
Enable
Control
Bit
SPIE
Exit from Wait
Yes Yes
Exit
from
Halt
Note: The SPI interrupt events are connected to
the same interrupt vector (see Interrupts chapter). They generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).
66/124
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ST7LITE0xY0, ST7LITESxY0
SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.8 Register Description CONTROL REGISTER (SPICR)

Read/Write Reset Value: 0000 xxxx (0xh)
70
SPIE SPE SPR2 MSTR CPOL CPHA SPR1 SPR0
Bit 7 = SPIE Serial Peripheral Interrupt Enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SPI interrupt is generated whenever
SPIF=1, MODF=1 or OVR=1 in the SPICSR register
Bit 6 = SPE Serial Peripheral Output Enable. This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS
=0 (see Section 11.3.5.1 Master Mode Fault
(MODF)). The SPE bit is cleared by reset, so the
SPI peripheral is not initially connected to the ex­ternal pins. 0: I/O pins free for general purpose I/O 1: SPI I/O pin alternate functions enabled
Bit 5 = SPR2 Divider Enable. This bit is set and cleared by software and is cleared by reset. It is used with the SPR[1:0] bits to set the baud rate. Refer to Table 15 SPI Master
mode SCK Frequency.
0: Divider by 2 enabled 1: Divider by 2 disabled
Note: This bit has no effect in slave mode.
Bit 4 = MSTR Master Mode. This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS
=0 (see Section 11.3.5.1 Master Mode Fault
(MODF)).
0: Slave mode 1: Master mode. The function of the SCK pin
changes from an input to an output and the func­tions of the MISO and MOSI pins are reversed.
Bit 3 = CPOL Clock Polarity. This bit is set and cleared by software. This bit de­termines the idle state of the serial Clock. The CPOL bit affects both the master and slave modes. 0: SCK pin has a low level idle state 1: SCK pin has a high level idle state
Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by re­setting the SPE bit.
Bit 2 = CPHA Clock Phase. This bit is set and cleared by software. 0: The first clock transition is the first data capture
edge.
1: The second clock transition is the first capture
edge.
Note: The slave must have the same CPOL and CPHA settings as the master.
Bits 1:0 = SPR[1:0] Serial Clock Frequency. These bits are set and cleared by software. Used with the SPR2 bit, they select the baud rate of the SPI serial clock SCK output by the SPI in master mode.
Note: These 2 bits have no effect in slave mode.
Table 15. SPI Master mode SCK Frequency
Serial Clock SPR2 SPR1 SPR0
f
/4 1 0 0
CPU
f
/8 0 0 0
CPU
f
/16 0 0 1
CPU
f
/32 1 1 0
CPU
f
/64 0 1 0
CPU
f
/128 0 1 1
CPU
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ST7LITE0xY0, ST7LITESxY0
SERIAL PERIPHERAL INTERFACE (Cont’d) CONTROL/STATUS REGISTER (SPICSR)
Read/Write (some bits Read Only) Reset Value: 0000 0000 (00h)
70
SPIF WCOL OVR MODF - SOD SSM SSI
Bit 7 = SPIF Serial Peripheral Data Transfer Flag
(Read only).
This bit is set by hardware when a transfer has been completed. An interrupt is generated if SPIE=1 in the SPICR register. It is cleared by a software sequence (an access to the SPICSR register followed by a write or a read to the SPIDR register).
0: Data transfer is in progress or the flag has been
cleared.
1: Data transfer between the device and an exter-
nal device has been completed.
Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR reg­ister is read.
Bit 6 = WCOL Write Collision status (Read only). This bit is set by hardware when a write to the SPIDR register is done during a transmit se­quence. It is cleared by a software sequence (see
Figure 42).
0: No write collision occurred 1: A write collision has been detected
Bit 5 = OVR SPI Overrun error (Read only). This bit is set by hardware when the byte currently being received in the shift register is ready to be transferred into the SPIDR register while SPIF = 1 (See Section 11.3.5.2). An interrupt is generated if SPIE = 1 in the SPICR register. The OVR bit is cleared by software reading the SPICSR register. 0: No overrun error 1: Overrun error detected
Bit 4 = MODF Mode Fault flag (Read only). This bit is set by hardware when the SS
pin is pulled low in master mode (see Section 11.3.5.1
Master Mode Fault (MODF)). An SPI interrupt can
be generated if SPIE=1 in the SPICR register. This bit is cleared by a software sequence (An access to the SPICSR register while MODF=1 followed by a write to the SPICR register). 0: No master mode fault detected 1: A fault in master mode has been detected
Bit 3 = Reserved, must be kept cleared.
Bit 2 = SOD SPI Output Disable. This bit is set and cleared by software. When set, it disables the alternate function of the SPI output (MOSI in master mode / MISO in slave mode) 0: SPI output enabled (if SPE=1) 1: SPI output disabled
Bit 1 = SSM SS
Management.
This bit is set and cleared by software. When set, it disables the alternate function of the SPI SS and uses the SSI bit value instead. See Section
11.3.3.2 Slave Select Management.
0: Hardware management (SS
nal pin)
1: Software management (internal SS
trolled by SSI bit. External SS al-purpose I/O)
Bit 0 = SSI SS
Internal Mode.
This bit is set and cleared by software. It acts as a ‘chip select’ by controlling the level of the SS select signal when the SSM bit is set. 0 : Slave selected 1 : Slave deselected
DATA I/O REGISTER (SPIDR)
Read/Write Reset Value: Undefined
70
D7 D6 D5 D4 D3 D2 D1 D0
The SPIDR register is used to transmit and receive data on the serial bus. In a master device, a write to this register will initiate transmission/reception of another byte.
Notes: During the last clock cycle the SPIF bit is set, a copy of the received data byte in the shift register is moved to a buffer. When the user reads the serial peripheral data I/O register, the buffer is actually being read.
While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read.
Warning: A write to the SPIDR register places data directly into the shift register for transmission.
A read to the SPIDR register returns the value lo­cated in the buffer and not the content of the shift register (see Figure 37).
pin
managed by exter-
signal con-
pin free for gener-
slave
68/124
1
SERIAL PERIPHERAL INTERFACE (Cont’d)
Table 16. SPI Register Map and Reset Values
ST7LITE0xY0, ST7LITESxY0
Address
(Hex.)
31
32
33
Register
Label
SPIDR
Reset Value
SPICR
Reset Value
SPICSR
Reset Value
76543210
MSB
xxxxxxx
SPIE
0
SPIF
0
SPE
0
WCOL
0
SPR20MSTR0CPOL
x
OVR
0
MODF
00
CPHA
x
SOD
0
SPR1
x
SSM
0
LSB
x
SPR0
x
SSI
0
69/124
1
ST7LITE0xY0, ST7LITESxY0

11.4 8-BIT A/D CONVERTER (ADC)

11.4.1 Introduction

The on-chip Analog to Digital Converter (ADC) pe­ripheral is a 8-bit, successive approximation con­verter with internal sample and hold circuitry. This peripheral has up to 5 multiplexed analog input channels (refer to device pin out description) that allow the peripheral to convert the analog voltage levels from up to 5 different sources.
The result of the conversion is stored in a 8-bit Data Register. The A/D converter is controlled through a Control/Status Register.

11.4.2 Main Features

8-bit conversion
Up to 5 channels with multiplexed input
Linear successive approximation
Dual input range
–0 to V
DD
or
– 0V to 250mV
Data register (DR) which contains the results
Conversion complete status flag
On/off bit (to reduce consumption)
Fixed gain operational amplifier (x8) (not
available on ST7LITES5 devices)

11.4.3 Functional Description

11.4.3.1 Analog Power Supply
The block diagram is shown in Figure 44. V
and VSS are the high and low level reference
DD
voltage pins. Conversion accuracy may therefore be impacted
by voltage drops and noise in the event of heavily loaded or badly decoupled power supply lines.
For more details, refer to the Electrical character­istics section.
11.4.3.2 Input Voltage Amplifier
The input voltage can be amplified by a factor of 8 by enabling the AMPSEL bit in the ADAMP regis­ter.
When the amplifier is enabled, the input range is 0V to 250 mV.
For example, if V
= 5V, then the ADC can con-
DD
vert voltages in the range 0V to 250mV with an ideal resolution of 2.4mV (equivalent to 11-bit res­olution with reference to a V
to VDD range).
SS
For more details, refer to the Electrical character­istics section.
Note: The amplifier is switched on by the ADON bit in the ADCCSR register, so no additional start­up time is required when the amplifier is selected by the AMPSEL bit.
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1
Figure 44. ADC Block Diagram
ST7LITE0xY0, ST7LITESxY0
AIN0
AIN1
AINx
f
CPU
DIV 2
ANALOG
MUX
0
1
7
3
x 1 or x 8
AMPSEL bit
(ADCAMP Register)
DIV 4
R
ADC
ADCDR
1
0
(ADCAMP Register)
SLOW
bit
CH2 CH10EOC SPEED ADON 0 CH0
HOLD CONTROL
C
f
ADC
0
ADCCSR
ADC
ANALOG TO DIGITAL
CONVERTER
D2 D1D3D7 D6 D5 D4 D0
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ST7LITE0xY0, ST7LITESxY0
8-BIT A/D CONVERTER (ADC) (Cont’d)
11.4.3.3 Digital A/D Conversion Result
The conversion is monotonic, meaning that the re­sult never decreases if the analog input does not and never increases if the analog input does not.
If the input voltage (V to V
(high-level voltage reference) then the
DDA
conversion result in the DR register is FFh (full scale) without overflow indication.
If input voltage (V
(low-level voltage reference) then the con-
V
SSA
version result in the DR register is 00h. The A/D converter is linear and the digital result of
the conversion is stored in the ADCDR register. The accuracy of the conversion is described in the parametric section.
is the maximum recommended impedance
R
AIN
for an analog input signal. If the impedance is too high, this will result in a loss of accuracy due to leakage and sampling not being completed in the alloted time.
11.4.3.4 A/D Conversion Phases
The A/D conversion is based on two conversion phases as shown in Figure 45:
Sample capacitor loading [duration: t
During this phase, the V measured is loaded into the C capacitor.
A/D conversion [duration: t
During this phase, the A/D conversion is computed (8 successive approximations cycles) and the C
sample capacitor is disconnected
ADC
from the analog input pin to get the optimum analog to digital conversion accuracy.
The total conversion time:
t
CONV = tSAMPLE
While the ADC is on, these two phases are contin­uously repeated.
At the end of each conversion, the sample capaci­tor is kept loaded with the previous measurement load. The advantage of this behaviour is that it minimizes the current consumption on the analog pin in case of single input channel measurement.
11.4.3.5 Software Procedure
Refer to the control/status register (CSR) and data register (DR) in Section 11.4.6 for the bit defini­tions and to Figure 45 for the timings.
) is greater than or equal
AIN
) is lower than or equal to
AIN
]
SAMPLE
ADC
sample
+ t
HOLD
input voltage to be
AIN
HOLD
]
ADC Configuration
The analog input ports must be configured as in­put, no pull-up, no interrupt. Refer to the «I/O ports» chapter. Using these pins as analog inputs does not affect the ability of the port to be read as a logic input.
In the CSR register:
– Select the CH[2:0] bits to assign the analog
channel to be converted.
ADC Conversion
In the CSR register:
– Set the ADON bit to enable the A/D converter
and to start the first conversion. From this time on, the ADC performs a continuous conver­sion of the selected channel.
When a conversion is complete
– The EOC bit is set by hardware. – No interrupt is generated. – The result is in the DR register and remains
valid until the next conversion has ended.
A write to the ADCCSR register (with ADON set) aborts the current conversion, resets the EOC bit and starts a new conversion.
Figure 45. ADC Conversion Timings
ADON
HOLD CONTROL
t
SAMPLE
t
CONV
t
HOLD
ADCCSR WRITE
OPERATION
EOC BIT SET

11.4.4 Low Power Modes

Mode Description
WAIT No effect on A/D Converter
A/D Converter disabled.
HALT
After wakeup from Halt mode, the A/D Con­verter requires a stabilization time before ac­curate conversions can be performed.
Note: The A/D converter may be disabled by reset­ting the ADON bit. This feature allows reduced power consumption when no conversion is needed and between single shot conversions.
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11.4.5 Interrupts

None
8-BIT A/D CONVERTER (ADC) (Cont’d)

11.4.6 Register Description

ST7LITE0xY0, ST7LITESxY0
CONTROL/STATUS REGISTER (ADCCSR)
Read/Write Reset Value: 0000 0000 (00h)
70
EOC SPEED ADON 0 0 CH2 CH1 CH0
DATA REGISTER (ADCDR)
Read Only Reset Value: 0000 0000 (00h)
70
D7 D6 D5 D4 D3 D2 D1 D0
Bit 7 = EOC Conversion Complete This bit is set by hardware. It is cleared by soft­ware reading the result in the DR register or writing to the CSR register. 0: Conversion is not complete 1: Conversion can be read from the DR register
Bit 6 = SPEED ADC clock selection This bit is set and cleared by software. It is used together with the SLOW bit to configure the ADC clock speed. Refer to the table in the SLOW bit de-
Bits 7:0 = D[7:0] Analog Converted Value This register contains the converted analog value in the range 00h to FFh.
Note: Reading this register reset the EOC flag.
AMPLIFIER CONTROL REGISTER (ADCAMP)
Read/Write Reset Value: 0000 0000 (00h)
scription.
70
Bit 5 = ADON A/D Converter and Amplifier On This bit is set and cleared by software.
0000SLOW
0: A/D converter and amplifier are switched off 1: A/D converter and amplifier are switched on
Note: Amplifier not available on ST7LITES5 devices
Bit 7:4 = Reserved. Forced by hardware to 0. Bit 3 = SLOW Slow mode
This bit is set and cleared by software. It is used together with the SPEED bit to configure the ADC
Bits 4:3 = Reserved. must always be cleared.
Bits 2:0 = CH[2:0] Channel Selection These bits are set and cleared by software. They select the analog input to convert.
Channel Pin
AIN0 0 0 0 AIN1 0 0 1 AIN2 0 1 0 AIN3 0 1 1 AIN4 1 0 0
1
CH2 CH1 CH0
Notes:
1. The number of pins AND the channel selection
clock speed as shown on the table below.
f
ADC
f
/2 00
CPU
f
CPU
f
/4 1x
CPU
Bit 2 = AMPSEL Amplifier Selection Bit This bit is set and cleared by software. For ST7LITES5 devices, this bit must be kept at its re­set value (0). 0: Amplifier is not selected 1: Amplifier is selected
Note: When AMPSEL=1 it is mandatory that f be less than or equal to 2 MHz.
varies according to the device. Refer to the device pinout.
2. A write to the ADCCSR register (with ADON set) aborts the current conversion, resets the EOC bit and starts a new conversion.
Bits 1:0 = Reserved. Forced by hardware to 0. Note: If ADC settings are changed by writing the
ADCAMP register while the ADC is running, a dummy conversion is needed before obtaining re­sults with the new settings.
AMP-
SEL
00
SLOW SPEED
01
ADC
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ST7LITE0xY0, ST7LITESxY0
Table 17. ADC Register Map and Reset Values
Address
(Hex.)
34h
35h
36h
Register
Label
ADCCSR
Reset Value
ADCDR
Reset Value
ADCAMP
Reset Value
76543210
EOC
0
D7
0
0000
SPEED0ADON
000
D6
0
D5
0
D4
CH2
0
D3
0
0
SLOW0AMPSEL
D2
0
0
CH1
0
D1
0
00
CH0
0
D0
0
74/124
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12 INSTRUCTION SET

ST7LITE0xY0, ST7LITESxY0

12.1 ST7 ADDRESSING MODES

The ST7 Core features 17 different addressing modes which can be classified in seven main groups:
Addressing Mode Example
Inherent nop Immediate ld A,#$55 Direct ld A,$55 Indexed ld A,($55,X) Indirect ld A,([$55],X) Relative jrne loop Bit operation bset byte,#5
The ST7 Instruction set is designed to minimize the number of bytes required per instruction: To do so, most of the addressing modes may be subdi­vided in two submodes called long and short:
– Long addressing mode is more powerful be-
cause it can use the full 64 Kbyte address space, however it uses more bytes and more CPU cy­cles.
– Short addressing mode is less powerful because
it can generally only access page zero (0000h ­00FFh range), but the instruction size is more compact, and faster. All memory to memory in­structions use short addressing modes only (CLR, CPL, NEG, BSET, BRES, BTJT, BTJF, INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP)
The ST7 Assembler optimizes the use of long and short addressing modes.
Table 18. ST7 Addressing Mode Overview
Mode Syntax
Inherent nop + 0 Immediate ld A,#$55 + 1 Short Direct ld A,$10 00..FF + 1 Long Direct ld A,$1000 0000..FFFF + 2
No Offset Direct Indexed ld A,(X) 00..FF
Short Direct Indexed ld A,($10,X) 00..1FE + 1 Long Direct Indexed ld A,($1000,X) 0000..FFFF + 2 Short Indirect ld A,[$10] 00..FF 00..FF byte + 2 Long Indirect ld A,[$10.w] 0000..FFFF 00..FF word + 2 Short Indirect Indexed ld A,([$10],X) 00..1FE 00..FF byte + 2 Long Indirect Indexed ld A,([$10.w],X) 0000..FFFF 00..FF word + 2 Relative Direct jrne loop PC-128/PC+127 Relative Indirect jrne [$10] PC-128/PC+127 Bit Direct bset $10,#7 00..FF + 1 Bit Indirect bset [$10],#7 00..FF 00..FF byte + 2 Bit Direct Relative btjt $10,#7,skip 00..FF + 2 Bit Indirect Relative btjt [$10],#7,skip 00..FF 00..FF byte + 3
Note:
1. At the time the instruction is executed, the Program Counter (PC) points to the instruction following JRxx.
Destination/
Source
Pointer
Address
(Hex.)
1)
1)
00..FF byte + 2
Pointer
Size
(Hex.)
Length
(Bytes)
+ 0 (with X register) + 1 (with Y register)
+ 1
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ST7LITE0xY0, ST7LITESxY0
ST7 ADDRESSING MODES (cont’d)

12.1.1 Inherent

All Inherent instructions consist of a single byte. The opcode fully specifies all the required informa­tion for the CPU to process the operation.
Inherent Instruction Function
NOP No operation TRAP S/W Interrupt
WFI
HALT
RET Subroutine Return IRET Interrupt Subroutine Return SIM Set Interrupt Mask RIM Reset Interrupt Mask SCF Set Carry Flag RCF Reset Carry Flag RSP Reset Stack Pointer LD Load CLR Clear PUSH/POP Push/Pop to/from the stack INC/DEC Increment/Decrement TNZ Test Negative or Zero CPL, NEG 1 or 2 Complement MUL Byte Multiplication SLL, SRL, SRA, RLC,
RRC SWAP Swap Nibbles

12.1.2 Immediate

Immediate instructions have 2 bytes, the first byte contains the opcode, the second byte contains the operand value.
Immediate Instruction Function
LD Load CP Compare BCP Bit Compare AND, OR, XOR Logical Operations ADC, ADD, SUB, SBC Arithmetic Operations
Wait For Interrupt (Low Power Mode)
Halt Oscillator (Lowest Power Mode)
Shift and Rotate Operations

12.1.3 Direct

In Direct instructions, the operands are referenced by their memory address.
The direct addressing mode consists of two sub­modes:
Direct (Short)
The address is a byte, thus requires only 1 byte af­ter the opcode, but only allows 00 - FF addressing space.
Direct (Long)
The address is a word, thus allowing 64 Kbyte ad­dressing space, but requires 2 bytes after the op­code.

12.1.4 Indexed (No Offset, Short, Long)

In this mode, the operand is referenced by its memory address, which is defined by the unsigned addition of an index register (X or Y) with an offset.
The indirect addressing mode consists of three submodes:
Indexed (No Offset)
There is no offset (no extra byte after the opcode), and allows 00 - FF addressing space.
Indexed (Short)
The offset is a byte, thus requires only 1 byte after the opcode and allows 00 - 1FE addressing space.
Indexed (Long)
The offset is a word, thus allowing 64 Kbyte ad­dressing space and requires 2 bytes after the op­code.

12.1.5 Indirect (Short, Long)

The required data byte to do the operation is found by its memory address, located in memory (point­er).
The pointer address follows the opcode. The indi­rect addressing mode consists of two submodes:
Indirect (Short)
The pointer address is a byte, the pointer size is a byte, thus allowing 00 - FF addressing space, and requires 1 byte after the opcode.
Indirect (Long)
The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode.
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ST7 ADDRESSING MODES (cont’d)

12.1.6 Indirect Indexed (Short, Long)

This is a combination of indirect and short indexed addressing modes. The operand is referenced by its memory address, which is defined by the un­signed addition of an index register value (X or Y) with a pointer value located in memory. The point­er address follows the opcode.
The indirect indexed addressing mode consists of two submodes:
Indirect Indexed (Short)
The pointer address is a byte, the pointer size is a byte, thus allowing 00 - 1FE addressing space, and requires 1 byte after the opcode.
Indirect Indexed (Long)
The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode.
Table 19. Instructions Supporting Direct, Indexed, Indirect and Indirect Indexed Addressing Modes
ST7LITE0xY0, ST7LITESxY0

12.1.7 Relative Mode (Direct, Indirect)

This addressing mode is used to modify the PC register value by adding an 8-bit signed offset to it.
Available Relative Direct/
Indirect Instructions
JRxx Conditional Jump CALLR Call Relative
The relative addressing mode consists of two sub­modes:
Relative (Direct)
The offset follows the opcode.
Relative (Indirect)
The offset is defined in memory, of which the ad­dress follows the opcode.
Function
Long and Short
Instructions
LD Load CP Compare AND, OR, XOR Logical Operations
ADC, ADD, SUB, SBC
BCP Bit Compare
Short Instructions Only Function
CLR Clear INC, DEC Increment/Decrement TNZ Test Negative or Zero CPL, NEG 1 or 2 Complement BSET, BRES Bit Operations
BTJT, BTJF
SLL, SRL, SRA, RLC, RRC
SWAP Swap Nibbles CALL, JP Call or Jump subroutine
Arithmetic Addition/subtrac­tion operations
Bit Test and Jump Opera­tions
Shift and Rotate Operations
Function
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ST7LITE0xY0, ST7LITESxY0

12.2 INSTRUCTION GROUPS

The ST7 family devices use an Instruction Set consisting of 63 instructions. The instructions may
Load and Transfer LD CLR Stack operation PUSH POP RSP Increment/Decrement INC DEC Compare and Tests CP TNZ BCP Logical operations AND OR XOR CPL NEG Bit Operation BSET BRES Conditional Bit Test and Branch BTJT BTJF Arithmetic operations ADC ADD SUB SBC MUL Shift and Rotates SLL SRL SRA RLC RRC SWAP SLA Unconditional Jump or Call JRA JRT JRF JP CALL CALLR NOP RET Conditional Branch JRxx Interruption management TRAP WFI HALT IRET Condition Code Flag modification SIM RIM SCF RCF
Using a prebyte
The instructions are described with 1 to 4 bytes. In order to extend the number of available op-
codes for an 8-bit CPU (256 opcodes), three differ­ent prebyte opcodes are defined. These prebytes modify the meaning of the instruction they pre­cede.
The whole instruction becomes:
PC-2 End of previous instruction PC-1 Prebyte PC Opcode PC+1 Additional word (0 to 2) according to the
number of bytes required to compute the effective address
be subdivided into 13 main groups as illustrated in the following table:
PDY 90 Replace an X based instruction using
immediate, direct, indexed, or inherent addressing mode by a Y one.
PIX 92 Replace an instruction using direct, di-
rect bit or direct relative addressing mode to an instruction using the corre­sponding indirect addressing mode. It also changes an instruction using X indexed addressing mode to an instruc­tion using indirect X indexed addressing mode.
PIY 91 Replace an instruction using X indirect
indexed addressing mode by a Y one.

12.2.1 Illegal Opcode Reset

In order to provide enhanced robustness to the de­vice against unexpected behavior, a system of ille­gal opcode detection is implemented. If a code to
These prebytes enable instruction in Y as well as indirect addressing modes to be implemented. They precede the opcode of the instruction in X or the instruction using direct addressing mode. The prebytes are:
be executed does not correspond to any opcode or prebyte value, a reset is generated. This, com­bined with the Watchdog, allows the detection and recovery from an unexpected fault or interference.
Note: A valid prebyte associated with a valid op­code forming an unauthorized combination does not generate a reset.
78/124
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ST7LITE0xY0, ST7LITESxY0
INSTRUCTION GROUPS (cont’d)
Mnemo Description Function/Example Dst Src H I N Z C
ADC Add with Carry A = A + M + C A M H N Z C ADD Addition A = A + M A M H N Z C AND Logical And A = A . M A M N Z BCP Bit compare A, Memory tst (A . M) A M N Z BRES Bit Reset bres Byte, #3 M BSET Bit Set bset Byte, #3 M BTJF Jump if bit is false (0) btjf Byte, #3, Jmp1 M C BTJT Jump if bit is true (1) btjt Byte, #3, Jmp1 M C CALL Call subroutine CALLR Call subroutine relative CLR Clear reg, M 0 1 CP Arithmetic Compare tst(Reg - M) reg M N Z C CPL One Complement A = FFH-A reg, M N Z 1 DEC Decrement dec Y reg, M N Z HALT Halt 0 IRET Interrupt routine return Pop CC, A, X, PC H I N Z C INC Increment inc X reg, M N Z JP Absolute Jump jp [TBL.w] JRA Jump relative always JRT Jump relative JRF Never jump jrf * JRIH Jump if ext. interrupt = 1 JRIL Jump if ext. interrupt = 0 JRH Jump if H = 1 H = 1 ? JRNH Jump if H = 0 H = 0 ? JRM Jump if I = 1 I = 1 ? JRNM Jump if I = 0 I = 0 ? JRMI Jump if N = 1 (minus) N = 1 ? JRPL Jump if N = 0 (plus) N = 0 ? JREQ Jump if Z = 1 (equal) Z = 1 ? JRNE Jump if Z = 0 (not equal) Z = 0 ? JRC Jump if C = 1 C = 1 ? JRNC Jump if C = 0 C = 0 ? JRULT Jump if C = 1 Unsigned < JRUGE Jump if C = 0 Jmp if unsigned >= JRUGT Jump if (C + Z = 0) Unsigned >
79/124
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ST7LITE0xY0, ST7LITESxY0
INSTRUCTION GROUPS (cont’d)
Mnemo Description Function/Example Dst Src H I N Z C
JRULE Jump if (C + Z = 1) Unsigned <=
LD Load dst <= src reg, M M, reg N Z
MUL Multiply X,A = X * A A, X, Y X, Y, A 0 0
NEG Negate (2's compl) neg $10 reg, M N Z C
NOP No Operation
OR OR operation A = A + M A M N Z
POP Pop from the Stack pop reg reg M
pop CC CC M H I N Z C
PUSH Push onto the Stack push Y M reg, CC
RCF Reset carry flag C = 0 0
RET Subroutine Return
RIM Enable Interrupts I = 0 0
RLC Rotate left true C C <= Dst <= C reg, M N Z C
RRC Rotate right true C C => Dst => C reg, M N Z C
RSP Reset Stack Pointer S = Max allowed
SBC Subtract with Carry A = A - M - C A M N Z C
SCF Set carry flag C = 1 1
SIM Disable Interrupts I = 1 1
SLA Shift left Arithmetic C <= Dst <= 0 reg, M N Z C
SLL Shift left Logic C <= Dst <= 0 reg, M N Z C
SRL Shift right Logic 0 => Dst => C reg, M 0 Z C
SRA Shift right Arithmetic Dst7 => Dst => C reg, M N Z C
SUB Subtraction A = A - M A M N Z C
SWAP SWAP nibbles Dst[7..4] <=> Dst[3..0] reg, M N Z
TNZ Test for Neg & Zero tnz lbl1 N Z
TRAP S/W trap S/W interrupt 1
WFI Wait for Interrupt 0
XOR Exclusive OR A = A XOR M A M N Z
80/124
1

13 ELECTRICAL CHARACTERISTICS

13.1 PARAMETER CONDITIONS

ST7LITE0xY0, ST7LITESxY0
Unless otherwise specified, all voltages are re­ferred to V
SS
.

13.1.1 Minimum and Maximum values

Unless otherwise specified the minimum and max­imum values are guaranteed in the worst condi­tions of ambient temperature, supply voltage and frequencies by tests in production on 100% of the devices with an ambient temperature at T and T
max (given by the selected temperature
A=TA
=25°C
A
range). Data based on characterization results, design
simulation and/or technology characteristics are indicated in the table footnotes and are not tested in production. Based on characterization, the min­imum and maximum values refer to sample tests and represent the mean value plus or minus three times the standard deviation (mean±3Σ).

13.1.2 Typical values

Unless otherwise specified, typical data are based
=25°C, VDD=5V (for the 4.5V≤VDD≤5.5V
on T
A
voltage range), V voltage range) and V
2.4V≤V
3V voltage range). They are given only
DD
=3.3V (for the 3V≤VDD≤3.6V
DD
=2.7V (for the
DD
as design guidelines and are not tested.

13.1.3 Typical curves

Unless otherwise specified, all typical curves are given only as design guidelines and are not tested.

13.1.4 Loading capacitor

The loading conditions used for pin parameter measurement are shown in Figure 46.

13.1.5 Pin input voltage

The input voltage measurement on a pin of the de­vice is described in Figure 47.
Figure 47. Pin input voltage
ST7 PIN
V
IN
Figure 46. Pin loading conditions
C
L
ST7 PIN
81/124
1
ST7LITE0xY0, ST7LITESxY0

13.2 ABSOLUTE MAXIMUM RATINGS

Stresses above those listed as “absolute maxi­mum ratings” may cause permanent damage to the device. This is a stress rating only and func­tional operation of the device under these condi-

13.2.1 Voltage Characteristics

Symbol Ratings Maximum value Unit
VDD - V
V
IN
V
ESD(HBM)
SS
Supply voltage 7.0 Input voltage on any pin
1) & 2)
Electrostatic discharge voltage (Human Body Model)

13.2.2 Current Characteristics

Symbol Ratings Maximum value Unit
I
VDD
I
VSS
Total current into VDD power lines (source) Total current out of VSS ground lines (sink) Output current sunk by any standard I/O and control pin 20
I
IO
Output current sunk by any high sink I/O pin 40 Output current source by any I/Os and control pin - 25
I
INJ(PIN)
2) & 4)
Injected current on RESET pin ± 5 Injected current on PB1 pin
5)
Injected current on any other pin
ΣI
INJ(PIN)
2)
Total injected current (sum of all I/O and control pins)

13.2.3 Thermal Characteristics

tions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
VSS-0.3 to VDD+0.3
see section 13.7.2 on page 93
3)
3)
6)
6)
75
150
+5
± 5
± 20
V
mA
Symbol Ratings Value Unit
T
STG
T
J
Storage temperature range -65 to +150 °C Maximum junction temperature (see Section 14.2 THERMAL CHARACTERISTICS)
Notes:
1. Directly connecting the I/O pins to V
tion occurs (for example, due to a corrupted program counter). To guarantee safe operation, this connection has to be done through a pull-up or pull-down resistor (typical: 10k for I/Os). Unused I/O pins must be tied in the same way to V or VSS according to their reset configuration. For reset pin, please refer to Figure 80.
2. I respected, the injection current must be limited externally to the I
must never be exceeded. This is implicitly insured if VIN maximum is respected. If VIN maximum cannot be
INJ(PIN)
while a negative injection is induced by VIN<VSS.
3. All power (V
4. Negative injection disturbs the analog performance of the device. In particular, it induces leakage currents throughout
) and ground (VSS) lines must always be connected to the external supply.
DD
DD
or V
could damage the device if an unexpected change of the I/O configura-
SS
value. A positive injection is induced by VIN>V
INJ(PIN)
DD
DD
the device including the analog inputs. To avoid undesirable effects on the analog functions, care must be taken:
- Analog input pins must have a negative injection less than 0.8 mA (assuming that the impedance of the analog voltage is lower than the specified limits)
- Pure digital pins must have a negative injection less than 1.6mA. In addition, it is recommended to inject the current as far as possible from the analog input pins.
5. No negative current injection allowed on PB1 pin.
6. When several inputs are submitted to a current injection, the maximum ΣI
and negative injected currents (instantaneous values). These results are based on characterisation with ΣI mum current injection on four I/O port pins of the device.
is the absolute sum of the positive
INJ(PIN)
INJ(PIN)
maxi-
82/124
1
ST7LITE0xY0, ST7LITESxY0

13.3 OPERATING CONDITIONS

13.3.1 General Operating Conditions: Suffix 6 Devices

T
= -40 to +85°C unless otherwise specified.
A
Symbol Parameter Conditions Min Max Unit
f
= 8 MHz. max., 2.4 5.5
V
f
CLKIN
DD
Supply voltage
External clock frequency on CLKIN pin
OSC
= 16 MHz. max. 3.3 5.5
f
OSC
3.3VV
2.4V≤V
5.5V up to 16
DD
<3.3V up to 8
DD
V
MHz
Figure 48. f
FUNCTIONALITY
NOT GUARANTEED
IN THIS AREA
Maximum Operating Frequency Versus V
CLKIN
f
[MHz]
CLKIN
16
8
4
1 0
2.0 2.4
2.7
3.3 3.5 4.0 4.5 5.0
Note: For further information on clock management and f
on page 24
Supply Voltage
DD
FUNCTIONALITY GUARANTEED IN THIS AREA (UNLESS OTHERWISE STATED IN THE TABLES OF PARAMETRIC DATA)
SUPPLY VOLTAGE [V]
5.5
description, refer to Figure 14 in section 7
CLKIN
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1
ST7LITE0xY0, ST7LITESxY0

13.3.2 Operating Conditions with Low Voltage Detector (LVD)

T
= -40 to 85°C, unless otherwise specified
A
Symbol Parameter Conditions Min Typ Max Unit
1)
V
IT+
V
IT-
(LVD)
V
hys
Vt
POR
t
g(VDD)
I
DD(LVD
(LVD)
Reset release threshold
rise)
(V
DD
Reset generation threshold
fall)
(V
DD
LVD voltage threshold hysteresis V VDD rise time rate Filtered glitch delay on V
2)
DD
) LVD/AVD current consumption 220 µA
High Threshold Med. Threshold Low Threshold
High Threshold Med. Threshold Low Threshold
(LVD)
-V
IT-
(LVD)
IT+
Not detected by the LVD 150 ns
Notes:
1. Not tested in production.
2. Not tested in production. The V
When the V
slope is outside these values, the LVD may not ensure a proper reset of the MCU.
DD
rise time rate condition is needed to ensure a correct device power-on and LVD reset.
DD

13.3.3 Auxiliary Voltage Detector (AVD) Thresholds

T
= -40 to 85°C, unless otherwise specified
A
Symbol Parameter Conditions Min Typ Max Unit
High Threshold Med. Threshold Low Threshold
High Threshold Med. Threshold Low Threshold
IT+
V
DD
-V
(AVD)
IT-
(AVD)
fall 0.45 V
V
V
V
V
IT+
IT-
hys
(AVD)
(AVD)
IT-
1=>0 AVDF flag toggle threshold
rise)
(V
DD
0=>1 AVDF flag toggle threshold
fall)
(V
DD
AVD voltage threshold hysteresis V Voltage drop between AVD flag set
and LVD reset activation
4.00
3.40 1)
2.65
3.80
3.20
2.40
1)
4.25
3.60
2.90
4.05
3.40
2.70
4.50
3.80
3.15
4.30
3.65
2.90
1)
1)
1)
200 mV
20 20000 µs/V
4.40
3.90
3.20
4.30
3.70
2.90
4.70
4.10
3.40
4.60
3.90
3.20
5.00
4.30
3.60
4.90
4.10
3.40
150 mV
V
V
84/124
1
ST7LITE0xY0, ST7LITESxY0

13.3.4 Internal RC Oscillator and PLL

The ST7 internal clock can be supplied by an internal RC oscillator and PLL (selectable by option byte).
Symbol Parameter Conditions Min Typ Max Unit
V
DD(RC)
DD(x4PLL)
V
DD(x8PLL)
t
STARTUP
The RC oscillator and PLL characteristics are temperature-dependent and are grouped in two tables.
13.3.4.1 Devices with “6” order code suffix (tested for T
Symbol Parameter Conditions Min Typ Max Unit
1)
f
RC
ACC
RC
I
DD(RC)
t
su(RC)
f
PLL
t
LOCK
t
STAB
ACC
PLL
t
w(JIT)
JIT
PLL
I
DD(PLL)
Internal RC Oscillator operating voltage 2.4 5.5 x4 PLL operating voltage 2.4 3.3 x8 PLL operating voltage 3.3 5.5
PLL Startup time 60
= -40 to +85°C) @ VDD = 4.5 to 5.5V
A
Internal RC oscillator fre­quency
Accuracy of Internal RC oscillator with RCCR=RCCR0
2)
RC oscillator current con­sumption
RCCR = FF (reset value), T RCCR = RCCR0
2 )
,TA=25°C, VDD=5V 1000 TA=25°C,VDD=4.5 to 5.5V -1 +1% T
=-40 to +85°C, VDD=5V -5 +2 %
A
T
=0 to +85°C, VDD=4.5 to 5.5V -2
A
=25°C,VDD=5V 970
T
A
=25°C, VDD=5V 760
A
3)
PLL input clock (f
cycles
+2
3)
RC oscillator setup time TA=25°C,VDD=5V 10 x8 PLL input clock 1 PLL Lock time PLL Stabilization time
x8 PLL Accuracy
5)
5)
= 1MHz@TA=25°C, VDD=4.5 to 5.5V 0.1
f
RC
f
= 1MHz@TA=-40 to +85°C, VDD=5V 0.1
RC
PLL jitter period fRC = 1MHz 8 PLL jitter (∆f
CPU/fCPU
)1
PLL current consumption TA=25°C 600
3)
2ms 4ms
4)
4)
6)
6)
3)
VV
PLL
kHz
3)
%
µA
2)
µs
MHz
% %
kHz
%
µA
)
Notes:
1. If the RC oscillator clock is selected, to improve clock stability and frequency accuracy, it is recommended to place a
decoupling capacitor, typically 100nF, between the V
and VSS pins as close as possible to the ST7 device.
DD
2. See “INTERNAL RC OSCILLATOR ADJUSTMENT” on page 24
3. Data based on characterization results, not tested in production
4. Averaged over a 4ms period. After the LOCKED bit is set, a period of t
5. After the LOCKED bit is set ACC
is max. 10% until t
PLL
has elapsed. See Figure 13 on page 25.
STAB
is required to reach ACC
STAB
accuracy
PLL
6. Guaranteed by design.
85/124
1
ST7LITE0xY0, ST7LITESxY0
OPERATING CONDITIONS (Cont’d)
13.3.4.2 Devices with ‘”6” order code suffix (tested for T
Symbol Parameter Conditions Min Typ Max Unit
1)
f
RC
ACC
I
DD(RC)
t
su(RC)
f
PLL
t
LOCK
t
STAB
ACC
t
w(JIT)
JIT
PLL
I
DD(PLL)
Internal RC oscillator fre­quency
Accuracy of Internal RC oscillator when calibrated
RC
with RCCR=RCCR1
RC oscillator current con­sumption
RC oscillator setup time TA=25°C,VDD=3V 10 x4 PLL input clock 0.7 PLL Lock time
5)
PLL Stabilization time
x4 PLL Accuracy
PLL
PLL jitter period fRC = 1MHz 8 PLL jitter (∆f
CPU/fCPU
PLL current consumption TA=25°C 190
RCCR = FF (reset value), T RCCR=RCCR1
2)
,TA=25°C, VDD= 3V 700 TA=25°C,VDD=3V -2 +2 % T
=25°C,VDD=2.7 to 3.3V -25 +25 %
2)3)
A
T
=-40 to +85°C, VDD=3V -15 15 %
A
=25°C,VDD=3V 700
T
A
5)
= 1MHz@TA=25°C, VDD=2.7 to 3.3V 0.1
f
RC
= 1MHz@TA=40 to +85°C, VDD= 3V 0.1
f
RC
)1
= -40 to +85°C) @ VDD = 2.7 to 3.3V
A
=25°C, VDD= 3.0V 560
A
3)
3)
2ms 4ms
4)
4)
6)
6)
3)
2)
kHz
µA
µs
MHz
% %
kHz
%
µA
Notes:
1. If the RC oscillator clock is selected, to improve clock stability and frequency accuracy, it is recommended to place a
decoupling capacitor, typically 100nF, between the V
and VSS pins as close as possible to the ST7 device.
DD
2. See “INTERNAL RC OSCILLATOR ADJUSTMENT” on page 24.
3. Data based on characterization results, not tested in production
4. Averaged over a 4ms period. After the LOCKED bit is set, a period of t
5. After the LOCKED bit is set ACC
is max. 10% until t
PLL
has elapsed. See Figure 13 on page 25.
STAB
is required to reach ACC
STAB
accuracy
PLL
6. Guaranteed by design.
86/124
1
OPERATING CONDITIONS (Cont’d)
)
ST7LITE0xY0, ST7LITESxY0
Figure 49. RC Osc Freq vs V (Calibrated with RCCR1: 3V @ 25°C)
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
Output Freq (MHz
0.60
0.55
0.50
2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 4 VDD (V)
Figure 50. RC Osc Freq vs V (Calibrated with RCCR0: 5V@ 25°C)
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
Output Freq. (MHz)
0.20
0.10
0.00
2.533.544.555.56 Vdd (V)
DD
DD
@ TA=25°C
-45° 0° 25° 90° 105° 130°
Figure 51. temperature @ V (Calibrated with RCCR0: 5V @ 25°C
RC Accuracy
Figure 52. RC Osc Freq vs V
1.80
1.60
1.40
1.20
1.00
0.80
0.60
Output Freq. (MHz)
0.40
0.20
0.00
Typical RC oscillator Accuracy vs
=5V
DD
2 1 0
-1
-2
-3
-4
(
)
*
-5
-45 025 85
) tested in production
(
*
2.4 2.7 3 3.3 3.75 4 4.5 5 5.5 6
(*)
Temperature (°C)
Vdd (V)
and RCCR Value
DD
)
(
*
125
rccr=00h rccr=64h rccr=80h rccr=C0h rccr=FFh
Figure 53. PLL f
f
CPU/fCPU
Max
0
Min
CPU/fCPU
versus time
t
w(JIT)
t
w(JIT)
t
87/124
1
ST7LITE0xY0, ST7LITESxY0
OPERATING CONDITIONS (Cont’d)
Figure 54. PLLx4 Output vs CLKIN frequency
7.00
6.00
5.00
4.00
3.00
Output Frequency (MHz)
2.00
1.00
Note: f
11.522.53
= f
OSC
Ext ernal Input Cloc k Frequency (MHz)
/2*PLL4
CLKIN
3.3 3
2.7
Figure 55. PLLx8 Output vs CLKIN frequency
11.00
9.00
7.00
5.00
3.00
Output Frequency (MHz)
1.00
0.85 0.9 1 1.5 2 2.5
External Input Clock Frequency (MHz)
Note: f
OSC
= f
CLKIN
/2*PLL8
5.5 5
4.5 4
88/124
1

13.4 SUPPLY CURRENT CHARACTERISTICS

ST7LITE0xY0, ST7LITESxY0
The following current consumption specified for the ST7 functional operating modes over tempera­ture range does not take into account the clock
vice consumption, the two current values must be added (except for HALT mode for which the clock is stopped).
source current consumption. To get the total de-

13.4.1 Supply Current

= -40 to +85°C unless otherwise specified
T
A
Symbol Parameter Conditions Typ Max Unit
Supply current in RUN mode Supply current in WAIT mode f Supply current in SLOW mode f Supply current in SLOW WAIT mode f
I
DD
Supply current in HALT mode
5)
f
=8MHz
CPU
=8MHz
CPU
=250kHz
CPU
=5.5V
DD
V
=250kHz
CPU
-40°C≤TA≤+85°C
T
= +85°C 5
A
Notes:
1. CPU running with memory access, all I/O pins in input mode with a static value at V
in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.
2. All I/O pins in input mode with a static value at V driven by external square wave, LVD disabled.
3. SLOW mode selected with f (no load), all peripherals in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.
V
SS
4. SLOW-WAIT mode selected with f
VDD or VSS (no load), all peripherals in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.
based on f
CPU
based on f
CPU
5. All I/O pins in output mode with a static value at V
tested in production at V
max and f
DD
CPU
max.
or VSS (no load), all peripherals in reset state; clock input (CLKIN)
DD
divided by 32. All I/O pins in input mode with a static value at VDD or
OSC
divided by 32. All I/O pins in input mode with a static value at
OSC
(no load), LVD disabled. Data based on characterization results,
SS
1)
2)
+105°C
A
4.50 7.00
3)
4)
0.75 1.13
0.65 1
1.75 2.70 mA
0.50 10
TBD TBD
µA-40°C≤T
100
or VSS (no load), all peripherals
DD
Figure 56. Typical IDD in RUN vs. f
5.0
4.0
3.0
2.0
Idd (mA)
1.0
0.0
8MHz 4MHz 1MHz
2.4 2.7 3.7 4. 5 5 5.5
Vdd (V)
CPU
Figure 57. Typical IDD in SLOW vs. f
0.80
0.70
0.60
0.50
0.40
0.30
Idd (mA)
0.20
0.10
0.00
250kHz
125kHz
62.5k Hz
2.4 2.7 3.7 4.5 5 5.5
Vdd (V)
CPU
89/124
1
ST7LITE0xY0, ST7LITESxY0
SUPPLY CURRENT CHARACTERISTICS (Cont’d)
Figure 58. Typical I
2.0
1.5
1.0
Idd (mA)
0.5
0.0
2.4 2.7 3.7 4.5 5 5.5
DD
8MHz 4MHz 1MHz
in WAIT vs. f
Vdd (V)
CPU
Figure 59. Typical IDD in SLOW-WAIT vs. f
0.70
0.60
0.50
0.40
0.30
Idd (mA)
0.20
0.10
0.00
250kHz 125kHz
62.5kHz
2.4 2.7 3.7 4.5 5 5.5
Vdd (V)
CPU
Figure 60. Typical IDD vs. Temperature at V
DD
5.00
4.50
4.00
3.50
3.00
2.50
2.00
Idd (mA)
1.50
1.00
0.50
0.00
= 5V and f
-45 25 90 130
= 8MHz
CPU
Temperature (°C)
RUN WAIT SLOW SLOW WAIT

13.4.2 On-chip peripherals

Symbol Parameter Conditions Typ Unit
f
=4MHz VDD=3.0V 150
I
DD(AT)
I
DD(SPI)
I
DD(ADC)
12-bit Auto-Reload Timer supply current
SPI supply current
2)
ADC supply current when converting
1)
3)
1. Data based on a differential IDD measurement between reset configuration (timer stopped) and a timer running in PWM mode at f
2. Data based on a differential I tion (data sent equal to 55h).
3. Data based on a differential I plifier off.
=8MHz.
cpu
measurement between reset configuration and a permanent SPI master communica-
DD
measurement between reset configuration and continuous A/D conversions with am-
DD
CPU
f
=8MHz VDD=5.0V 250
CPU
f
=4MHz VDD=3.0V 50
CPU
f
=8MHz VDD=5.0V 300
CPU
=3.0V 780
V
f
ADC
=4MHz
DD
V
=5.0V 1100
DD
µA
90/124
1

13.5 CLOCK AND TIMING CHARACTERISTICS

ST7LITE0xY0, ST7LITESxY0
Subject to general operating conditions for V
DD
, f
OSC
, and TA.

13.5.1 General Timings

Symbol Parameter
t
c(INST)
t
v(IT)
Instruction cycle time f
Interrupt reaction time t
v(IT)
= ∆t
c(INST)
+ 10
1)
3)
Conditions Min Typ
=8MHz
CPU
f
=8MHz
CPU
2312t
250 375 1500 ns
10 22 t
1.25 2.75 µs
2)
Max Unit

13.5.2 External Clock Source

Symbol Parameter Conditions Min Typ Max Unit
V
CLKINH
V
CLKINL
t
w(CLKINH)
t
w(CLKINL)
t
r(CLKIN)
t
f(CLKIN)
I
CLKIN input pin high level voltage CLKIN input pin low level voltage V
CLKIN high or low time
CLKIN rise or fall time
CLKIN Input leakage current VSS≤VIN≤V
L
4)
4)
see Figure 61
DD
0.7xV
15
SS
DD
V
DD
0.3xV
DD
15
±1 µA
Notes:
1. Guaranteed by Design. Not tested in production.
2. Data based on typical application software.
3. Time measured between interrupt event and interrupt vector fetch. t
ish the current instruction execution.
is the number of t
c(INST)
4. Data based on design simulation and/or technology characteristics, not tested in production.
cycles needed to fin-
CPU
CPU
CPU
V
ns
Figure 61. Typical Application with an External Clock Source
90%
V
CLKINH
V
CLKINL
EXTERNAL CLOCK SOURCE
t
r(CLKIN)
t
fCLKIN)
10%
CLKIN
t
w(CLKINH)
I
L
t
w(CLKINL)
f
OSC
ST72XXX
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ST7LITE0xY0, ST7LITESxY0

13.6 MEMORY CHARACTERISTICS

T
= -40°C to 105°C, unless otherwise specified
A

13.6.1 RAM and Hardware Registers

Symbol Parameter Conditions Min Typ Max Unit
V
RM
Data retention mode

13.6.2 FLASH Program Memory

Symbol Parameter Conditions Min Typ Max Unit
V
t
t
N
I
prog
RET
DD
Operating voltage for Flash write/erase
DD
Programming time for 1~32 bytes Programming time for 1.5 kBytes Data retention Write erase cycles
RW
Supply current

13.6.3 EEPROM Data Memory

1)
HALT mode (or RESET) 1.6 V
2.4 5.5
2)
4)
TA=−40 to +105°C 5 10 T
=+25°C 0.24 0.48
A
TA=+55°C TA=+25°C 10K
3)
20 years
7)
Read / Write / Erase
modes
f
= 8MHz, VDD = 5.5V
CPU
2.6
6)
No Read/No Write Mode 100 µA
Power down mode / HALT 0 0.1 µA
V
ms
s
cycles
mA
Symbol Parameter Conditions Min Typ Max Unit
V
t
N
DD
prog
t
ret
RW
Operating voltage for EEPROM write/erase
Programming time for 1~32 bytes Data retention Write erase cycles
4)
T
=−40 to +105°C 5 10
A
TA=+55°C
3)
TA=+25°C 300K
2.4 5.5
20 years
7)
Notes:
1. Minimum V
isters (only in HALT mode). Guaranteed by construction, not tested in production.
supply voltage without losing data stored in RAM (in HALT mode or under RESET) or in hardware reg-
DD
2. Up to 32 bytes can be programmed at a time.
3. The data retention time increases when the T
decreases.
A
4. Data based on reliability test results and monitored in production.
5. Data based on characterization results, not tested in production.
6. Guaranteed by Design. Not tested in production.
7. Design target value pending full product characterization.
V
ms
cycles
92/124
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ST7LITE0xY0, ST7LITESxY0

13.7 EMC (ELECTROMAGNETIC COMPATIBILITY) CHARACTERISTICS

Susceptibility tests are performed on a sample ba­sis during product characterization.

13.7.1 Functional EMS (Electro Magnetic Susceptibility)

Based on a simple running application on the product (toggling two -+LEDs through I/O ports), the product is stressed by two electro magnetic events until a failure occurs (indicated by the LEDs).
ESD: Electro-Static Discharge (positive and
negative) is applied on all pins of the device until a functional disturbance occurs. This test conforms with the IEC 1000-4-2 standard.
FTB: A Burst of Fast Transient voltage (positive
and negative) is applied to V
and VSS through
DD
a 100pF capacitor, until a functional disturbance occurs. This test conforms with the IEC 1000-4­4 standard.
A device reset allows normal operations to be re­sumed. The test results are given in the table be­low based on the EMS levels and classes defined in application note AN1709.
13.7.1.1 Designing hardened software to avoid noise problems
EMC characterization and optimization are per­formed at component level with a typical applica-
tion environment and simplified MCU software. It should be noted that good EMC performance is highly dependent on the user application and the software in particular.
Therefore it is recommended that the user applies EMC software optimization and prequalification tests in relation with the EMC level requested for his application.
Software recommendations:
The software flowchart must include the manage­ment of runaway conditions such as:
– Corrupted program counter – Unexpected reset – Critical Data corruption (control registers...)
Prequalification trials:
Most of the common failures (unexpected reset and program counter corruption) can be repro­duced by manually forcing a low state on the RE­SET pin or the Oscillator pins for 1 second.
To complete these trials, ESD stress can be ap­plied directly on the device, over the range of specification values. When unexpected behaviour is detected, the software can be hardened to pre­vent unrecoverable errors occurring (see applica­tion note AN1015).
Symbol Parameter Conditions
V
V
FESD
FFTB
Voltage limits to be applied on any I/O pin to induce a functional disturbance
Fast transient voltage burst limits to be applied through 100pF on V tional disturbance
DD
and V
pins to induce a func-
DD

13.7.2 EMI (Electromagnetic interference)

Based on a simple application running on the product (toggling two LEDs through the I/O ports),
VDD=5V, TA=+25°C, f conforms to IEC 1000-4-2
V
=5V, TA=+25°C, f
DD
conforms to IEC 1000-4-4
emission test is in line with the norm SAE J 1752/3 which specifies the board and the loading of each pin.
the product is monitored in terms of emission. This
Table 20: EMI emissions
Symbol Parameter Conditions
V
=5V, TA=+25°C,
DD
S
EMI
Note:
1. Data based on characterization results, not tested in production.
Peak level
SO16 package, conforming to SAE J 1752/3
Monitored
Frequency Band
0.1MHz to 30MHz 8 14
130MHz to 1GHz 26 28 SAE EMI Level 3.5 4 -
=8MHz
OSC
=8MHz
OSC
Max vs. [f
1/4MHz 1/8MHz
OSC/fCPU
]
Level/ Class
2B
3B
Unit
dBµV30MHz to 130MHz 27 32
93/124
1
ST7LITE0xY0, ST7LITESxY0
EMC CHARACTERISTICS (Cont’d)

13.7.3 Absolute Maximum Ratings (Electrical Sensitivity)

Based on two different tests (ESD and LU) using specific measurement methods, the product is stressed in order to determine its performance in terms of electrical sensitivity.
ESD absolute maximum ratings
Symbol Ratings Conditions Maximum value
V
ESD(HBM)
Notes:
1. Data based on characterization results, not tested in production.
Electro-static discharge voltage (Human Body Model)
13.7.3.1 Electro-Static Discharge (ESD)
Electro-Static Discharges (a positive then a nega­tive pulse separated by 1 second) are applied to the pins of each sample according to each pin combination. The sample size depends on the number of supply pins in the device (3 parts*(n+1) supply pin). This test conforms to the JESD22­A114A standard.
T
=+25°C
A
conforming to JESD22-A114
4000 V
1)
Unit
13.7.3.2 Static Latch-Up
LU: Two complementary static tests are
required on 10 parts to assess the latch-up performance. A supply overvoltage (applied to
(applied to each input, output and configurable I/ O pin) are performed on each sample. These test are compliant with the EIA/JESD 78 IC latch-up standard.
each power supply pin) and a current injection
Electrical Sensitivities
Symbol Parameter Conditions Class
T
=+25°C
LU Static latch-up class
Note:
1. Class description: A Class is an STMicroelectronics internal specification. All its limits are higher than the JEDEC spec-
ifications, that means when a device belongs to Class A it exceeds the JEDEC standard. B Class strictly covers all the JEDEC criteria (international standard).
A
conforming to JESD78A
1)
II level A
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ST7LITE0xY0, ST7LITESxY0

13.8 I/O PORT PIN CHARACTERISTICS

13.8.1 General Characteristics

Subject to general operating conditions for V
Symbol Parameter Conditions Min Typ Max Unit
V
V
V
R
C
t
f(IO)out
t
r(IO)out
t
w(IT)in
Notes:
1. Data based on characterization results, not tested in production.
2. Configuration not recommended, all unused pins must be kept at a fixed voltage: using the output mode of the I/O for
example or an external pull-up or pull-down resistor (see Figure 66). Static peak current value taken at a fixed V based on design simulation and technology characteristics, not tested in production. This value depends on V perature values.
3. The R scribed in Figure 63).
4. To generate an external interrupt, a minimum pulse width has to be applied on an I/O port pin configured as an external interrupt source.
Input low level voltage V
IL
Input high level voltage 0.7xV
IH
Schmitt trigger voltage
hys
hysteresis
I
Input leakage current V
L
Static current consumption induced by
I
S
each floating input pin
Weak pull-up equivalent resistor
PU
I/O pin capacitance 5 pF
IO
Output high to low level fall time Output low to high level rise time External interrupt pulse time
pull-up equivalent resistor is based on a resistive transistor (corresponding I
PU
1)
2)
3)
1)
1)
4)
, f
DD
, and TA unless otherwise specified.
OSC
- 0.3 0.3xV
SS
DD
SS≤VIN≤VDD
Floating input mode 400
V
SS
VDD=5V 50 120 250
=V
IN
V
=3V 160
DD
CL=50pF Between 10% and 90%
1t
PU
V
DD
V
+ 0.3
DD
400 mV
±1
µA
k
25 25
IN
and tem-
DD
ns
CPU
value,
current characteristics de-
Figure 62. Two typical applications with unused I/O pin configured as input
V
DD
10k
Caution: During normal operation the ICCCLK pin must be pulled- up, internally or externally
(external pull-up of 10k mandatory in This is to avoid entering ICC mode unexpectedly during a reset. noisy environment).
Note: I/O can be left unconnected if it is configured as output (0 or 1) by the software. This has the advantage of greater EMC
robustness and lower cost.
Figure 63. Typical I
l
90
80
70
60
50
TO BE CHARACTERIZED
40
Ipu(uA)
30
20
10
0
22.533.544.555.56
vs. VDD with VIN=V
PU
Ta=140° C Ta=95°C Ta=25°C Ta=-45°C
Vdd(V)
ST7XXX
UNUSED I/O PORT
SS
10k
UNUSED I/O PORT
ST7XXX
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ST7LITE0xY0, ST7LITESxY0
I/O PORT PIN CHARACTERISTICS (Cont’d)

13.8.2 Output Driving Current

, f
Subject to general operating conditions for V
DD
Symbol Parameter Conditions Min Max Unit
Output low level voltage for a standard I/O pin when 8 pins are sunk at same time (see Figure 65)
1)
V
OL
Output low level voltage for a high sink I/O pin when 4 pins are sunk at same time (see Figure 66)
V
OH
when 4 pins are sourced at same time (see Figure 72)
Output high level voltage for an I/O pin
2)
Output low level voltage for a standard I/O pin when 8 pins are sunk at same time
1)3)
V
OL
(see Figure 64) Output low level voltage for a high sink I/O pin
when 4 pins are sunk at same time
OH
when 4 pins are sourced at same time
Output high level voltage for an I/O pin
2)3)
V
Output low level voltage for a standard I/O pin
OL
Output low level voltage for a high sink I/O pin
when 8 pins are sunk at same time
1)3)
V
when 4 pins are sunk at same time Output high level voltage for an I/O pin
2)3)
V
OH
when 4 pins are sourced at same time (see Figure 69)
, and TA unless otherwise specified.
CPU
IIO=+5mA TA≤85°C
85°C
T
A
=+2mA TA≤85°C
I
IO
=+20mA,TA≤85°C
I
IO
=5V
I
=+8mA TA≤85°C
DD
IO
V
=-5mA, TA≤85°C
I
IO
I
=-2mA TA≤85°C
IO
T
A
T
A
T
A
T
A
T
A
85°C
85°C
85°C
85°C
85°C
V
DD
V
DD
V
DD
V
DD
IIO=+2mA TA≤85°C
85°C
T
A
I
=+8mA TA≤85°C
IO
=3.3V
I
=-2mA TA≤85°C
IO
DD
V
T
A
T
A
85°C
85°C
V
DD
V
DD
IIO=+2mA TA≤85°C
85°C
T
A
I
=+8mA TA≤85°C
IO
I
=-2mA TA≤85°C
=2.7V
IO
DD
V
T
A
T
A
85°C
85°C
V
DD
V
DD
1.0
1.2
0.4
0.5
1.3
1.5
0.75
0.85
-1.5
-1.6
-0.8
-1.0
0.5
0.6
0.5
0.6
-0.8
-1.0
0.6
0.7
0.6
0.7
-0.9
-1.0
V
Notes:
1. The I
(I/O ports and control pins) must not exceed I
2. The I I
IO
current sunk must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of I
IO
current sourced must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of
IO
(I/O ports and control pins) must not exceed I
VSS
.
VDD
.
3. Not tested in production, based on characterization results.
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IO
I/O PORT PIN CHARACTERISTICS (Cont’d)
ST7LITE0xY0, ST7LITESxY0
Figure 64. Typical V
0.70
0.60
0.50
0.40
0.30
VOL at VDD=3.3V
0.20
0.10
0.00
0.01 1 2 3
Figure 65. Typical V
0.80
0.70
0.60
0.50
0.40
0.30
0.20
VOL at VDD=5V
0.10
0.00
0.0112345
at VDD=3.3V (standard)
OL
lio (m A)
at VDD=5V (standard)
OL
lio (mA)
-45°C 0°C 25°C 90°C 130°C
-45°C 0°C 25°C 90°C 130°C
Figure 66. Typical V
2.50
2.00
1.50
1.00
0.50
Vol (V) at VDD=5V (HS)
0.00 6 7 8 9 10 15 20 25 30 35 40
Figure 67. Typical V
1.20
1.00
0.80
0.60
0.40
Vol (V) at VDD=3V (HS)
0.20
0.00 67891015
at VDD=5V (high-sink)
OL
lio (mA)
at VDD=3V (high-sink)
OL
lio (mA)
-45 0°C 25°C 90°C 130°C
-45 0°C 25°C 90°C 130°C
Figure 68. Typical V
1.60
1.40
1.20
1.00
0.80
0.60
0.40
VDD-VOH at VDD=2.4V
0.20
0.00
-0.01 -1 -2
DD-VOH
lio (mA)
at VDD=2.4V
-45°C 0°C 25°C 90°C 130°C
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ST7LITE0xY0, ST7LITESxY0
Figure 69. Typical VDD-VOH at VDD=2.7V
1.20
1.00
0.80
0.60
0.40
VDD-VOH at VDD=2.7V
0.20
0.00
Figure 70. Typical V
1.60
1.40
1.20
1.00
0.80
0.60
VDD-VOH at VDD=3V
0.40
0.20
0.00
-0.01 -1 -2
-0.01 -1 -2 -3
lio(mA)
DD-VOH
lio (mA)
at VDD=3V
-45°C 0°C 25°C 90°C 130°C
-45°C 0°C 25°C 90°C 130°C
Figure 71. Typical V
2.50
2.00
1.50
1.00
VDD-VOH at VDD=4V
0.50
0.00
-0.01-1-2-3-4-5
Figure 72. Typical V
2.00
1.80
1.60
1.40
1.20
1.00
0.80
0.60
VDD-VOH at VDD=5V
0.40
0.20
0.00
TO BE CHARACTERIZED
-0.01-1-2-3-4-5
DD-VOH
lio (m A)
DD-VOH
lio (mA)
at VDD=4V
at VDD=5V
-45°C 0°C 25°C 90°C 130°C
-45°C 0°C 25°C 90°C 130°C
Figure 73. Typical V
0.70
0.60
0.50
0.40
0.30
0.20
Vol (V) at lio=2mA
0.10
0.00
2.4 2.7 3.3 5
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vs. VDD (standard I/Os)
OL
VDD (V)
-45 0°C 25°C 90°C 130°C
0.06
0.05
0.04
0.03
0.02
Vol (V) at lio=0.01mA
0.01
0.00
2.4 2.7 3.3 5
VDD (V)
-45 0°C 25°C 90°C 130°C
Figure 74. Typical VOL vs. VDD (high-sink I/Os)
ST7LITE0xY0, ST7LITESxY0
0.70
0.60
0.50
0.40
0.30
0.20
0.10
VOL vs VDD (HS) at lio=8mA
0.00
2.4 3 5
Figure 75. Typical V
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
VDD-VOH at lio=-5mA
1.00
0.90
0.80 45
VDD (V)
DD-VOH
VDD
vs. V
DD
-45 0°C 25°C 90°C 130°C
-45°C 0°C 25°C 90°C 130°C
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
VOL vs VDD (HS) at lio=20mA
VDD-VOH (V) at lio=-2mA
0.00
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
2.4 3 5
VDD (V )
2.42.7345
VDD (V )
-45 0°C 25°C 90°C 130°C
-45°C 0°C 25°C 90°C 130°C
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ST7LITE0xY0, ST7LITESxY0

13.9 CONTROL PIN CHARACTERISTICS

13.9.1 Asynchronous RESET
T
= -40°C to 105°C, unless otherwise specified
A
Pin
Symbol Parameter Conditions Min Typ Max Unit
V
V
V
V
R
t
w(RSTL)out
t
h(RSTL)in
t
g(RSTL)in
Input low level voltage V
IL
Input high level voltage 0.7xV
IH
Schmitt trigger voltage hysteresis
hys
Output low level voltage
OL
2)
1)
I
=+5mA TA≤85°C
VDD=5V
IO
I
IO
T
=+2mA TA≤85°C
T
Pull-up equivalent resistor
ON
3) 1)
VDD=5V 20 40 80 k
105°C
A
105°C
A
- 0.3 0.3xV
SS
DD
2V
0.5
0.2
Generated reset pulse duration Internal reset sources 30 µs External reset pulse hold time
4)
20 µs
Filtered glitch duration 200 ns
DD
V
+ 0.3
DD
V
1.0
1.2
0.4
V
0.5
Notes:
1. Data based on characterization results, not tested in production.
2. The I
sum of I
3. The R V
ILmax
current sunk must always respect the absolute maximum rating specified in section 13.2.2 on page 82 and the
IO
(I/O ports and control pins) must not exceed I
IO
pull-up equivalent resistor is based on a resistive transistor. Specified for voltages on RESET pin between
ON
and V
DD
VSS
.
4. To guarantee the reset of the device, a minimum pulse has to be applied to the RESET pin. All short pulses applied on pin with a duration below t
RESET
h(RSTL)in
can be ignored.
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