To obtain the most recent version of this datasheet,
please check at www.st.com>products>technical literature>datasheet
Please note that an errata sheet can be found at the end of this document on
and pay special attention to the Section “IMPORTANT NOTES” on page 116.
page 118
4/122
1
Page 5
1 INTRODUCTION
ST7LITE0, ST7SUPERLITE
The ST7LITE0 and ST7SUPERLITE are members
of the ST7 microcontrolle r family. All S T7 devices
are based on a common industry-standard 8-bit
core, featuring an enhanced instruction set.
The ST7LITE0 and ST7SUPERLITE feature
FLASH memory with byte-by-byte In-Circuit Programming (ICP) and In-Application Programming
(IAP) capability.
Under software control, the ST7LITE0 and
ST7SUPERLITE d evices can be plac ed in WAIT,
SLOW, or HALT mode, reducing power consumption when the application is in idle or standby state.
Figure 1. General Block D iagram
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 78.
LITE TIMER
w/ WATCHDOG
PORT A
ADDRESS AND DATA BUS
12-BIT AUTO-
RELOAD TIMER
PA7:0
(8 bits)
8-BIT CO RE
ALU
FLASH
MEMORY
(1 or 1.5K Byt es)
RAM
(128 Bytes)
DATA EEPROM
(128 Bytes)
SPI
PORT B
8-BIT ADC
PB4:0
(5 bits)
5/122
1
Page 6
ST7LITE0, ST7SU PERLITE
2 PIN DESCRI PTION
Figure 2. 16-Pin Package Pinout (150mil)
V
SS
V
DD
RESET
SS/AIN0/PB0
SCK/AIN1/P B1
MISO/AIN2/P B2
MOSI/AIN3/P B3
CLKIN/AIN4/P B4
1
2
3
ei3
4
5
6
ei2
7
8
ei0
ei1
PA0 (HS)/LTIC
16
(HS)
PA1
15
PA2
14
13
12
11
10
9
PA3
PA4
PA5
PA6/MCO/ICCC LK
PA7
(HS)/ATPWM0
(HS)
(HS)
(HS)/ICCDATA
(HS) 20mA high sink ca pability
associated external interrupt vect or
ei
x
6/122
1
Page 7
PIN DESCRIPTION (Cont’d)
Legend / Abbreviations for Tab le 1:
Type: I = input, O = output, S = supply
In/Output level: C= CMOS 0.15V
C
= CMOS 0.3VDD/0.7VDD with input trigger
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
2)
, PP = push-pull
Table 1. Device Pin Description
ST7LITE0, ST7SUPERLITE
1)
, ana = analog
Pin
n°
1V
2V
3RESET
4PB0/AIN0/SS
Pin Name
SS
DD
I/O C
Type
S Ground
S Main power supply
I/O C
5PB1/AIN1/SCKI/O C
6PB2/AIN2/MISOI/O C
7PB3/AIN3/MOSII/O C
8PB4/AIN4/CLKINI/O C
9PA7I/O C
10 PA6 /MCO/ICCCLKI/O C
PA5/
11
ICCDATA
I/O C
12 PA4I/O C
13 PA3I/O C
14 PA2/ATPWM0I/O C
15 PA1I/O C
16 PA0/LTICI/O C
LevelPort / Control
Main
Input
T
T
T
T
T
T
T
InputOutput
Output
float
int
wpu
OD
ana
XXTop priority non maskable interrupt (active low)
Xei3XXPort B0
XXXXPort B1ADC Analog Input 1 or SPI Clock
XXXXPort B2
Xei2XXPort B3
XXXXPort B4
Xei1XXPort A7
Function
(after reset)
PP
Alternate Function
ADC Analog Input 0 or SPI Slave
Select (active low)
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 Ou tput/In Circuit Com munication Clock .
Caution: During reset, this pin
XXXXPort A6
T
must be held at high level t o avoid
entering ICC mode unexpectedly
(this is guar anteed by the internal
pull-up if the appl icatio n leav es th e
pin floating).
HSXXXXPort A5In Circuit Communication Data
T
HSXXXXPort A4
T
HSXXXXPort A3
T
HSXXXXPort A2Auto-Reload Timer PWM0
T
HSXXXXPort A1
T
HSXei0XXPort A0Lite Timer Input Capture
T
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.
7/122
1
Page 8
ST7LITE0, ST7SU PERLITE
3 REGISTER & MEMORY MAP
As shown in Figure 3 and Figure 4, the MCU is capable of addressing 64K bytes of memorie s an d I/
O registers.
The available memory locations consist of up to
128 bytes of register locations, 128 bytes of RAM,
128 bytes of data EEPRO M and up to 1.5 Kbytes
of user program memory. The RAM space includes up to 64 bytes for the stack f rom 0C0h to
0FFh.
Figure 3. Me m ory Map (ST7 L IT E0)
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 by tes contain the user re set
and interrupt vectors.
The size of Flash Sector 0 is configurable by Option byte.
IMPORTANT: Memory locations marked as “Reserved” must neve r be ac cess ed. A cce ssing a reseved area c an have unpredictable e ffec ts on t he
device.
Short Addressing
RAM (zero page)
64 Bytes Stack
1000h
1001h
see section 7.1 on page 23
RCCR0
RCCR1
F9FFh
FA00h
FFDFh
FFE0h
FFFFh
Reserved
Flash Memory
(1.5K)
Interrupt & Reset Vectors
(see Table 7)
PROGRAM MEMORY
FA00h
FBFFh
FC00h
FFFFh
1.5K FLASH
0.5 Kb yt e s
SECTOR 1
1 Kbyte s
SECTOR 0
FFDEh
RCCR0
FFDFh
RCCR1
see section 7.1 on page 23
8/122
1
Page 9
REGISTER AND MEMORY MAP (Cont’d)
Figure 4. Me m ory Map (ST7SU P E R LI TE )
ST7LITE0, 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 7)
FC00h
FDFFh
FE00h
FFFFh
0080h
00BFh
00C0h
00FFh
Short Addressing
RAM (zero page)
64 Bytes S tack
1K FLASH
PROGRAM MEMORY
0.5 Kbytes
SECTOR 1
0.5 Kbytes
SECTOR 0
FFDEh
FFDFh
see section 7.1 on page 23
RCCR0
RCCR1
9/122
1
Page 10
ST7LITE0, ST7SU PERLITE
REGISTER AND MEMORY MAP (Cont’d)
Legend: x=unde fined, R/W=rea d/write
Table 2. Hardware Register Map
AddressBlock
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/Sta tus Registe r
Counter Register High
Counter Register Low
Auto-Reload Register High
Auto-Reload Register Low
PWM Output Control Register
PWM 0 Control/Status Register
1. The contents of the I/O p ort DR registers are readable only i n out put conf iguration. I n i nput conf iguration, 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.
11/122
1
Page 12
ST7LITE0, ST7SU PERLITE
4 FLASH PROGRAM MEMORY
4.1 In troduction
The ST7 single voltage extended Flash (XFlash) is
a non-volatile memory that can be electrically
erased and programmed either on a by te-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 organ isation allows each sector
to be erased and reprogrammed wi thout 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 against piracy
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, FLAS H
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 appli cation board a nd while the
application is running.
4.3.1 In-Circuit Programming (ICP)
ICP us es a pr ot o c ol c al l e d I CC ( I n- Ci r c ui t C om mu nication) 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 cod e 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 memo ry 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 c om mun ications protoc ol used t o
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.
12/122
1
Page 13
FLASH PROGRAM MEMORY (Cont’d)
ST7LITE0, ST7SUPERLITE
4.4 ICC interface
ICP needs a minimum of 4 and u p 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 use d
as outputs in the application, no signal i so lation 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 appli-
Figure 5. Typical ICC Interface
cation reset circuit if it drives more than 5mA at
high level (push pull output or pull-up resistor<1K).
A schottky diode can be u sed to isolate t he application RESET circuit in this case. When using a
classical RC network with R>1K or a reset management IC with open drain outpu t and pull-up resistor>1K, no additional com ponents 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 connec tor 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 t o the CLKIN pin of
the ST7 when the clock is not avai lable in the application or if the selected clock option is not programmed in the option byte.
5. During reset, this pin must be held at high level
to avoid entering ICC mode unexpectedly (this is
guaranteed by the internal pull-up if the application
leaves the pin floating).
APPLICATION
POWER SUPPLY
OPTIONAL
(See Note 3)
VDD
OPTIONAL
(See Note 4)
CLKIN
ST7
PROGRAMMING TOOL
ICC CONNECTOR
ICC Ca ble
ICC CONNECTOR
HE10 CONNECTORTYPE
975 3
1
246810
RESET
ICCCLK
ICCDATA
APPL ICATION BOARD
APPLICATION
RESET SOURCE
See Note 2
See Notes 1 and 5
See Note 1
APPLICATION
I/O
13/122
1
Page 14
ST7LITE0, ST7SU PERLITE
FLASH PROGRAM MEMORY (Cont’d)
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
Read out protection, when selected, makes it impossible to extract the m emory content from the
microcontroller, thus preventing piracy. 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 bei ng made to the mem ory 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 program ming and I CC protocol, refer to the ST7 Flash Programming Reference Manual and to th e ST7 ICC Protocol Reference Manual
Note: This register is reserved for programming
using ICP, IAP or other program ming methods. It
controls the XFlash p ro grammin g and erasing operations.
When an EPB or another programming tool is
used (in socket or ICP mode), the RASS k eys are
sent automatically.
Table 3. FLASH Register Map and Reset Values
Address
(Hex.)
002Fh
14/122
Register
Label
FCSR
Reset Value
76543210
00000
1
OPT
0
LAT
0
PGM
0
Page 15
5 DATA EEPRO M
ST7LITE0, ST7SUPERLITE
5.1 INTRODUCTION
The Electrically Erasable Programmable Read
Only Memory can be us ed as a non volatile back up for storing data. Using the EEPROM requires a
basic access protocol described in this chapter.
Figure 6. EEPR OM Block Dia gram
EECSR
ADDRESS
DECODER
0E2LAT00000E2PGM
4
DECODE R
ROW
5.2 MAIN FEATURES
■ Up to 32 Bytes programmed in the same cycle
■ EEPROM mono-voltage (charge pump)
■ Chained eras e and programmi n g cycles
■ Interna l c ont ro l of th e g l o bal p rog ra mming cycle
duration
■ WAIT mode management
■ Readout protection against piracy
HIGH VOLTAGE
PUMP
EEPROM
MEMORY MATRIX
(1 ROW = 32 x 8 BITS )
ADDRESS B U S
128128
4
4
DATA
MULTIPLEXER
DATA BUS
32 x 8 BITS
DATA L ATCHES
15/122
1
Page 16
ST7LITE0, ST7SU PERLITE
DATA EEPROM (Cont’d)
5.3 MEMORY ACCESS
The Data EEPROM memory read/write access
modes are con tr olled by the E2LAT bi t of t he EEPROM Control/Status register (EECSR). The flowchart in Figure 7 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 t he EECSR register is
cleared. In a read cycle, the byte to be accessed is
put on the dat a bus in l ess th an 1 CPU clock cycle .
This means that reading data from EEPROM
takes the same time as reading data from
EPROM, but this memory cannot be used to execute machine code.
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 7. Data EE P R OM Pr ogramming Fl owchart
READ MODE
E2LAT=0
E2PGM=0
the value is l atched in side the 32 data lat ches 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 EEPR OM cells. The effective
high address (row) is determined by the la st 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 w rite access data result) because
the data latches are only cleared at the end of the
programming cycle and by the falling e dge of the
E2LAT bit.
It is not possible to read the latched data.
This note is ilustrated by the Figure 9.
WRITE MODE
E2LAT=1
E2PGM= 0
16/122
1
READ BYTES
IN EEPROM AREA
CLEARED BY HA R D WARE
WRITEUPTO32BYTES
(with the same 11 MSB of the address)
IN EEPROM AREA
START PROGRAMMING CY CL E
E2PGM=1 (set by software)
E2LAT=1
01
E2LAT
Page 17
DATA EEPROM (Cont’d)
2
Figure 8. Data E
PROM Write Operation
ST7LITE0, ST7SUPERLITE
DEFINITION
E2LAT bit
E2PGM bit
Row / Byte
⇓
ROW
Byte 1Byte 2Byte 32
Set by USER application
0
1
...
N
PHASE 1
Writing data latchesWaiting E2PGM and E2LAT to fall
0123...30 31Physical Address
⇒
Nx20h...Nx20h+1Fh
Read operation impossible
Programming cycle
PHASE 2
00h...1Fh
20h...3Fh
Read operation possible
Cleared by hardware
Note: If a programming cycle is interrupted (by software or a reset action), the integrity of the data in mem-
ory is not guaranteed.
17/122
1
Page 18
ST7LITE0, ST7SU PERLITE
DATA EEPROM (Cont’d)
5.4 POWER SAVI NG MO DE S
Wait mode
The DATA EEPROM can enter WAIT mode on execution of the WFI inst ruction of the m icrocontroller or when the microcontroller enters Active-HALT
mode.The DATA EEPROM will immediately enter
this mode if there is no programming i n 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 exec utes the HA LT 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 t he
data on the bu s w ill not be latche d.
If a programming cycl e is interrupted (by software/
RESET action), the memory data will not be guaranteed.
5.6 Data EEPROM Read - ou t Protection
The read-out protection is enabled throug h an option bit (see section 15.1 on page 109).
When this option is selected, the programs and
data stored in the EEPROM memory are protected
against read-out piracy (including a re-write protection). In Flash devices, when this protection is
removed by reprogrammin g the Option Byte, the
entire Pr ogram memeory and EEPR OM is fir st automatically erased.
Note: B oth Progr am Memory and data EEP ROM
are protected using the same option bit.
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 m emory 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
19/122
1
Page 20
ST7LITE0, ST7SU PERLITE
6 CENTRAL PRO CESSING UNIT
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 mo des
■ Maskable hardware interrupts
■ Non-maskable software interrupt
6.3 CPU REGISTERS
The 6 CPU registers shown in Figure 10 are not
present in the memory mapping and are accessed
by specific instructions.
Figure 10. 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 operan ds 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 Cou nt er (P C )
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
158
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh
15
RESET VALUE = STACK HIGHER ADDRESS
20/122
PCH
RESET VALUE =
7
70
1C11HI NZ
1X11X1XX
70
8
PCL
1
0
PROGRAM COUNTER
CONDITION CODE REGISTER
STACK POINTER
X = Undefined Value
Page 21
ST7LITE0, ST7SUPERLITE
CPU REGISTERS (Cont’d)
CONDITION CODE REGISTER (CC)
Read/Write
Reset Value: 111x1xxx
70
111HINZC
The 8-bit Condition Code register c ontains the interrupt mask and four flags represent ative 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 between bits 3 and 4 of t he 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 interrupt or by software to disable all interrup ts 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 whe n I is cleared.
By default an interrupt routine is not in terruptable
because the I bi t 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 representative of the result sign of the last arithmeti c,
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
(i.e. the most significant bit is a logic 1).
This bit is accessed by the JRMI and JRPL instructions.
Zero
Bit 1 = Z
.
This bit is set and cleared by hardware. This bit indicates 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 b y hardware and software. 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
21/122
1
Page 22
ST7LITE0, ST7SU PERLITE
CPU REGISTERS (Cont’d)
Stack Pointer (SP)
Read/Write
Reset Value: 00 FFh
158
00000000
70
11SP5SP4SP3SP2SP1SP0
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 11).
Since the stack is 64 bytes deep, the 10 most significant bits are forced by hardw are. Following a n
MCU Reset, or after a Reset Stack Pointe r 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, wi thout indicating the s tack overflow. The previously
stored information is then o verwritten and therefore lost. The stack also wraps in case of an underflow.
The stack is used to save the retu rn 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 point ed to by the SP. Then the
other registers are stored in the next locations as
shown in Figure 11.
– 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 locat ions i n the sta ck ar ea.
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 ST7LITE0 and ST7SUPERLITE contain an internal RC oscillator with an accuracy of 1% for a
given device, temperat ure and voltage. It must be
calibrated to obtain the frequenc y 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 (F F h), 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 78. for more information on the frequency
and accuracy of the RC oscillator.
– To improve clock stability, it is recommended to
place a decoupling capacitor between the V
DD
ST7FLITE02 /
ST7FLITE05 /
ST7FLITES2 /
ST7FLITES5
Address
FFDEh
FFDFh
RCCRC onditions
V
=5V
RCCR0
RCCR1
and V
DD
T
=25°C
A
f
=1MHz
RC
V
=3.0V
DD
T
=25°C
A
f
=700KHz
RC
pins as close as possible to the ST7 de-
SS
ST7FLITE09
Address
1000h and
FFDEh
1001h andFFDFh
vice.
– These two bytes ar e syste matically pr ogrammed
by ST, including on FASTROM devices. Consequently, customers intending to use FASTROM
service must not use these two bytes.
Caution: If the voltage or temperature conditions
change in the application, the frequency may need
to be recalibrated.
Refer to application note AN1 324 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 f requency 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
the 3.3V to 5.5V range
DD
in
Refer to Section 15.1 for the option byte descrip-
tion.
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
23/122
1
Page 24
ST7LITE0, ST7SU PERLITE
Figure 12. PLL Output Frequency Timing
Diagram
LOCKED bit set
4/8 x
input
freq.
t
STAB
t
LOCK
t
STARTUP
Output freq.
t
When the PLL is started, after reset or wakeup
from Halt mode or AWUFH mode , it outputs the
clock after a delay of t
STARTUP
.
When the PLL output signal reaches the operating
Bit 1 = MCO
This bit is read/write by software and cleared by
hardware after a reset. This bit allows to ena ble
the MCO output clock.
0: MCO clock disabled, I/O port free for general
purpose I/O.
1: MCO clock enabled.
Bit 0 = SMS
This bit is read/write by software and cleared by
hardware after a reset. This bit selects the input
clock f
0: Normal mode (f
1: Slow mode (f
RC CONTROL REGISTER (RCCR)
Read / Write
Reset Value: 1111 1111 (FFh)
70
Main Clock Out enable
Slow Mode select
OSC
or f
/32.
OSC
CPU = fOSC
CPU = fOSC
/32)
frequency, the LOCKED bit in the SICSCR register
is set. Full PLL accur acy (ACC
a stabilization time of t
STAB
) is reached after
PLL
(see Figure 12 and
CR70 CR60 CR50 CR40 C R30 CR20 CR10
13.3.4 Internal RC Oscillator and PLL)
Refe r to section 7.5.4 on page 32 for a description
of the LOCKED bit in the SICSR register.
Bits 7:0 = CR[7:0]
justment Bits
These bits must be written immediately after reset
RC Oscillator Frequency Ad-
to adjust the RC oscillator frequency and to obtain
7.3 REGISTER DESCRIPTION
MAIN CLOCK CONTROL/STATUS REGISTER
(MCCSR)
Read / Write
Reset Value: 0000 0000 (00h)
an accuracy of 1%. The application ca n store the
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-
70
ent values in the register until the correct frequency is reached. The fastest met hod is to use a di-
0000000
MCOSMS
chotomy starting with 80h.
CR
0
Bits 7:2 = Reserved, must be kept cleared.
Table 5. Clock Register Map and Reset Values
Address
(Hex.)
0038h
0039h
24/122
Register
Label
MCCSR
Reset Value
RCCR
Reset Value
76543210
000000
CR70
1
CR60
1
CR50
1
MCO
0
CR40
1
1
CR30
1
CR20
1
CR10
1
SMS
0
CR0
1
Page 25
Figure 13. Clock Management Block Diagram
CR4CR7CR0CR1CR2CR3CR6 CR5RCCR
Tunable
Oscillator1% RC
PLL 1MHz -> 8MHz
PLL 1MHz -> 4MHz
ST7LITE0, ST7SUPERLITE
1MHz
8MHz
f
4MHz
OSC
CLKIN
f
OSC
7
/2 DIVIDER
/32 DIVIDER
Option byte
8-BIT
LITE TIMER COUNTER
f
/32
f
OSC
OSC
1
0
SMSMCO
0
MCCSR
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
)
MCO
25/122
1
Page 26
ST7LITE0, ST7SU PERLITE
7.4 RESET SEQUENCE MANAGER (RSM)
7.4.1 Introd uct i on
The reset sequence manager in cludes three RESET sources as shown in F igure 15:
■ External RESET source pulse
■ Internal LVD RESET (Low Voltage Detection)
■ Internal WATCHDOG RESET
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 s eque nc e cons i sts o f 3 p has es
as shown in Figure 14:
■ Active Phase depending on the RESET source
■ 256 CPU clock cycle delay
■ RESET vector fetch
The 256 CPU clock cycle delay allows the oscillator to stabilise and ensures that recovery has taken place from the Reset state.
Figure 15. Reset Block Diagram
V
DD
The RESET vector fetch phase duration is 2 clock
cycles.
If the PLL is enabled by opt ion byte, it outputs the
clock after an additional delay of t
STARTUP
(see
Figure 12).
Figure 14. RESET Sequence Phases
RESET
Active Phase
INTERNAL RESET
256 CLOCK CYCLES
FETCH
VECTOR
RESET
R
ON
FILTER
PULSE
GENERATOR
INTERNAL
RESET
WATCHDO G RESET
LVD RESET
26/122
1
Page 27
RESET SEQUENCE MANAGER (Cont’d)
ST7LITE0, ST7SUPERLITE
7.4.2 Asynchronous External RES ET
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 fixe d 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 16). This de-
tection 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 electr ical characteristics section.
7.4.3 External Power-On RESET
If the LVD is disabled by option byte, to start up t he
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 m inimum
DD
frequency.
OSC
Figure 16. RESET Sequences
V
DD
A proper reset signal for a slow rising V
supply
DD
can generally be provided b y an e xternal RC ne twork connected to the RESET
pin.
7.4.4 Internal Low Voltage Detector (LVD)
RESET
Two differen t 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 Fi gure 16.
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 16.
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
RUNRUN
INTERNAL RESET (256 T
VECTOR FETCH
WATCHDO G
RESET
ACTIVE
PHASE
t
w(RSTL)out
CPU
)
27/122
1
Page 28
ST7LITE0, ST7SU PERLITE
7.5 SYSTEM INTEGRITY MANAGEMENT (SI)
The System Integrity Managem ent block contains
the Low voltage Detector (LVD) and Auxiliary Voltage Detector (AVD) functions. It is managed by
the SICSR register.
7.5.1 Low Voltage Detector (LVD)
The Low Voltage Detector funct ion (LVD) generates a static reset when the V
below a V
IT-(LVD)
reference value. This means that
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 func t ion is illustrated in F igure 17.
The voltage threshold can be configured by option
byte to be low, m edium or high. S ee section 15.1
on page 109.
supply voltage is
DD
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 p ermitting the MCU to reset
other devices.
Notes:
The LVD is an optional function whi ch can be se-
lected by option byte. See section 15.1 o n page
109.
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.
Caution: If an LVD reset occurs after a watchdog
reset has oc curred, the LVD will take prio rity and
will clear the watchdog flag.
Figure 17. Low Voltage Detector vs Reset
V
DD
V
IT+
(LVD)
V
IT-
(LVD)
RESET
V
hys
28/122
1
Page 29
Figure 18. Reset and Supply Management Block Diagram
ST7LITE0, ST7SUPERLITE
RESET
V
SS
V
DD
RESET SEQUENCE
MANAGER
(RSM)
WATCHDOG
TIMER (WDG)
STATUS FLAG
SYSTEM INTEGRITYMANAGEMENT
SICSR
LOC
00
0
7
0
LOW VOLTAGE
DETEC TOR
AUXILIARY VOLTAGE
DETEC TOR
KED
(LVD)
(AVD)
RFIE
AVD Interrupt Request
AVDAVDLVD
F
0
29/122
1
Page 30
ST7LITE0, ST7SU PERLITE
SYSTEM INTEGRITY MANAGEMENT (Cont’d)
7.5.2 Auxiliary Voltage Detector (AVD)
The Voltage Detector function (AVD) is based on
an analog comparison between a V
V
IT+(AVD)
ply voltage (V
for falling voltage is lower than the V
reference value and the VDD main sup-
). The V
AVD
IT-(AVD)
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 S I CSR regi ster. Th is
bit is read only.
Caution: The AVD functions only if the LVD is enabled through the option byte.
and
refer-
7.5.2.1 Monitoring the V
Main Supply
DD
The AVD vol tage t hreshold v alue is rel ative to t he
selected LVD threshold configured by option b yte
(see section 15.1 on page 109).
If the AVD interrupt is enabled, an interrupt is generated when the voltag e crosses the V
V
IT-(AVD)
threshold (AVDF bit is set).
IT+(LVD)
or
In the case of a drop in voltage, the AVD i nterrupt
acts as an early warning, allowing software to shut
down safely before the LVD re sets the microcontroller. See Figure 19.
The interrupt on the rising edge is used to inform
the application that the V
warning state is over
DD
Figure 19. 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
01RESET
INTERRUPT Cleared by
DD
Early Warning Interrupt
(Power has dropped, MCU not
not yet in reset)
V
hyst
reset
01
INTERRUP T Cleared by
hardware
30/122
1
Page 31
SYSTEM INTEGRITY MANAGEMENT (Cont’d)
7.5.3 Low Power Modes
Mode Description
WAIT
HALT
No effect on SI. AVD interrupts cause the
device to exit from Wait mode.
The CRSR register is frozen.
The AVD remains active but the AVD interrupt cannot be used to exit from Halt mode.
7.5.3.1 Interrupts
The AVD interrupt event generates an interrupt if
the corresponding Enable Control Bit (AVDIE) is
ST7LITE0, ST7SUPERLITE
set and the interrupt mask in the CC register is reset (RIM instruction).
Exit
from
Wait
Flag
Enable
Control
Bit
Interrupt Event
AVD event AVDFAVDIEYesYes
Event
Exit
from
Halt
31/122
1
Page 32
ST7LITE0, ST7SU PERLITE
SYSTEM INTEGRITY MANAGEMENT (Cont’d)
7.5.4 Register Description
SYSTEM INTEGRITY (SI) CONTROL/STAT U S 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 and cleared by hardware. It is set automatically when the PLL reaches its operating frequency.
0: PLL not locked
1: PLL locked
Bit 2 = LV DRF
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 changes value. Refer to
Figure 19 for additional details
0: V
over AVD threshold
DD
1: V
under AVD threshold
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 f lag
changes (toggles). 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 t race 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 6. System Integrity Register Map and Reset Values
Address
(Hex.)
003Ah
Register
Label
SICSR
Reset Value
76543210
0000
LOCKED0LVDRFxAVDF0AVDIE
0
32/122
1
Page 33
8 INTE RRUPTS
ST7LITE0, ST7SUPERLITE
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 20.
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 c auses the conten ts o f the
saved registers to be recovered from the stack.
Note: As a consequence of the IRET instruction,
the I bit will be cleared a nd the main pro gram will
resume.
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 inte rrupt s ar e 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 proc essor to
leave the HALT low power mode (refer to the “Exit
from HALT“ column in the I nterrupt 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 will be serviced according to the flowchart on
Figure 20.
8.2 EXTERNAL INTERRUPTS
External interrupt vectors can be loaded into the
PC register if the corresponding ext ernal 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.
If several input pins, connected to the same interrupt vector, are configured as interrupts, their signals are logically NANDed before entering the
edge/level detection block.
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 on 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 f lag i s set
followed by a read or write of an associated register.
Note: the clearing sequence resets the internal
latch. A pending interrupt (i.e. waiting for being enabled) will therefore be lost if the clear sequence is
executed.
33/122
1
Page 34
ST7LITE0, ST7SU PERLITE
INTERRUPTS (Cont’d)
Figure 20. Inte rru pt P rocessing Flow c hart
AT TIMER Output Compare InterruptPWM0CSRnoFFEAh-FFEBh
LITE TIMER Input Capture InterruptLTCSRnoFFE6h-FFE7h
Lowest
Priority
Address
Vector
FFF8h-FFF9h
34/122
1
Page 35
INTERRUPTS (Cont’d)
ST7LITE0, ST7SUPERLITE
EXTERNAL INTERRUPT CONTROL REGISTER
(EICR)
Read/Write
Reset Value: 0000 0000 (00h)
70
IS31IS30IS21 IS20IS11IS10IS01 IS00
Bit 7:6 = IS3[1:0]
ei3 sensitivity
These bits define the interrupt sensitivity for ei3
(Port B0) according to Table 8.
Bit 5:4 = IS2[1:0]
ei2 sensitivity
These bits define the interrupt sensitivity for ei2
Bit 1:0 = IS0[1:0]
These bits define the interrupt sensitivity for ei0
(Port A0) according to Table 8.
Note: These 8 bits can be written only when the I
bit in the CC register is set.
Table 8. Interrupt Sensitivity Bits
ISx1 ISx0External Interrupt Sensitivity
00Falling edge & low level
01Rising edge only
10Falling edge only
11Rising and falling edge
.
ei0 sensitivity
(Port B3) according to Table 8.
Bit 3:2 = IS1[1:0]
ei1 sensitivity
These bits define the interrupt sensitivity for ei1
(Port A7) according to Table 8.
35/122
1
Page 36
ST7LITE0, ST7SU PERLITE
9 POWER SAVIN G MO DES
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 21): SLOW, WAIT (SLOW WAIT), AC-
TIVE 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 21. P ower Saving Mode Transi t io ns
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 i s 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 22. SLOW Mode Clock Transition
f
/32f
f
OSC
CPU
OSC
WAIT
SLOW WAIT
ACTIVE HALT
HALT
Low
POWER CONSUMPTION
f
SMS
OSC
NORMALRUN MODE
REQUEST
36/122
1
Page 37
POWER SAVING MODES (Cont’d)
ST7LITE0, ST7SUPERLITE
9.3 WAIT MODE
WAIT mode places the MCU in a low power consumption mode by stopping the CPU.
This pow er s av in g mode is s elected b y ca llin g the
‘WFI’ instr uc ti o n.
All peripherals remain active. During WAIT mode,
the I bit of the CC register is cleared, to enabl e all
interrupts. All other registers and me mory 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 r e main in W AIT mod e unt il a Rese t
or an Interrupt occurs, causing it to wake up.
Refer to Figure 23.
Figure 23. WAIT Mode Flow-chart
OSCILLATOR
WFI INSTRUCTION
N
INTERRUPT
Y
PERIPHERALS
CPU
I BIT
N
RESET
Y
OSCILLATOR
PERIPHERALS
CPU
I BIT
256 CPU CLOCK CYCLE
DELAY
OSCILLATOR
PERIPHERALS
CPU
I BIT
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.
37/122
1
Page 38
ST7LITE0, ST7SU PERLITE
POWER SAVING MODES (Cont’d)
9.4 ACTIVE-HALT AND HALT MODES
ACTIVE-HALT and HALT modes are the two lowest power consumption modes of the MC U. They
are both entered by executing the ‘HALT’ in struction. 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 rea l time clock
available. It is entered by exec uting 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 occur s. After
the start up delay, the CPU resumes operation
by fetching the reset vector which woke it up (see
Figure 25).
– 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 25).
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 inst ruction while th e Watchdo g
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 24. ACTIVE-HALT Timing Overview
ACTIVE
HALTRUNRUN
HALT
INSTRUCTION
[Active Halt Enabled]
256 CPU
CYCLE DELAY
RESET
OR
INTERRUPT
1)
FETCH
VECTOR
Figure 25. ACT IV E - HA LT Mode Flow-chart
HALT INSTRUCTION
(Active Halt enabled)
N
INTERRUPT
Y
OSCILLATOR
PERIPHERALS
CPU
I BIT
N
RESET
Y
3)
OSCILLATOR
PERIPHERALS
CPU
I BIT
256 CPU CLOCK CYCLE
DELAY
OSCILLATOR
PERIPHERALS
CPU
I BITS
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 ca n still b e a c ti v e.
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.
38/122
1
Page 39
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 m ode on reception of either a specific interrupt (see Table 7, “Interrupt
Mapping,” on page 34) 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 u se d to stabilize the o s c illator.
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 27).
When entering HALT mode, the I bit in the CC register is forced to 0 to e nable interrupt s. 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 t he “WD GHA LT” 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 109 for more details).
Figure 26. HALT Timing Overview
ST7LITE0, ST7SUPERLITE
Figure 27. HALT Mode Flow-chart
HALT INSTRUCTION
(Active Halt disabled)
WDGHALT
1
WATCHDOG
RESET
N
INTERRUPT
Y
1)
ENABLE
0
OSCILLATOR
PERIPHERALS
CPU
I BIT
N
3)
OSCILLATOR
PERIPHERALS
CPU
I BIT
256 CPU CLOCK CYCLE
OSCILLATOR
PERIPHERALS
CPU
I BITS
WATCHDOG
RESET
Y
DELAY
DISABLE
OFF
2)
OFF
OFF
0
ON
OFF
ON
4)
X
ON
ON
ON
4)
X
HALTRUNRUN
HALT
INSTRUCTION
[Active Halt disabled]
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 spec ific interrupt s can exit the MCU
from HALT mode (su ch as ex ternal i nterrupt). Refer to Table 7, “Interrupt Mapping,” on page 34 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 12).
39/122
1
Page 40
ST7LITE0, ST7SU PERLITE
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 t he
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.
– 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).
40/122
1
Page 41
10 I/O P ORTS
ST7LITE0, ST7SUPERLITE
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 Implem entation section). The generic I/O block diagram is
shown in Figure 28
10.2.1 Input Modes
The input configuration is sele cted 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 independent ly generate an int errupt
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 a re selected simultaneously as interrupt source, these
are logically ANDed. For t his reason if one of the
interrupt pins is tied low, it masks the other ones.
The external interrupts are hardware interrupts,
which means that the request latch (not accessible
directly by the application) is automatically cleared
when the corresponding interrupt vector is
fetched. To clear an unwanted pending interrupt
by software, the sensitivity bits in the EICR register
must be modified.
10.2.2 Output Modes
The output configuration is selecte d 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:
DRPush-pullOpen-drain
0V
1V
SS
DD
Vss
Floating
Note: When sw itching from input t o output m ode,
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.
10.2.3 Alternate Functions
When an on-chip peripheral is configured to use a
pin, the alternate function is au tomatically selected. This alternate function takes priority over the
standard I/O programming under the following
conditions:
– When the signal is comin g 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.
41/122
1
Page 42
ST7LITE0, ST7SU PERLITE
I/O PORTS (Cont’d)
Figure 28. I /O Port General B lo ck D iag ra m
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 ModePull-UpP-Buffe r
Input
Output
Floating with/without InterruptOff
Pull-up with/withou t InterruptOn
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
OnOn
INPUT
to V
SS
42/122
1
Page 43
I/O PORTS (Cont’d)
Table 10. I/O Port Configurations
ST7LITE0, ST7SUPERLITE
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
ENABLEOUTPUT
W
R
ALTERNATE INPUT
EXTERNAL INTERRUPT
SOURCE (ei
POLARITY
SELECTION
ANALOG INPUT
DR REGISTER ACCESS
DR
REGISTER
ALTERNATEALTERNATE
R/W
DATABUS
)
x
DATA BUS
V
2)
PAD
PUSH-PULL OUTPUT
DD
R
PU
ENABLEOUTPUT
DR REGISTER ACCESS
DR
REGISTER
ALTERNATEALTERNATE
R/W
DATA BUS
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 outp ut 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.
43/122
1
Page 44
ST7LITE0, ST7SU PERLITE
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 analo g
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 i s recommended not to
have clocking pins located close t o a sele cted analog pin.
WARNING: T he analog input voltage level must
be within the limits stated in the absolute maximum r a tings.
10.3 UNUSED I/O PINS
Unused I/O pins must be connected to fixed v oltage 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
YesYes
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 or true open drain.
Switching these I/O ports from one st ate to another should be done in a sequence that prevents unwanted side effects. Recommended safe transitions are illustrated in Figure 29 Other transitions
are potentially risky and should be avoided, since
they are likely to present unwanted side-effects
such as spurious interrupt generation.
The I/O port register configurations are summarised as follows.
Input (DDR=0)Output (DDR=1)
OR = 0 OR = 1OR = 0OR = 1
Page 45
I/O PORTS (Cont’d)
Table 12. I/O Port Register Map and Reset Values
ST7LITE0, ST7SUPERLITE
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
45/122
1
Page 46
ST7LITE0, ST7SU PERLITE
11 ON-CHIP PER IPHERALS
11.1 LI TE 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 30. Lite Timer Block Diagram
f
LTIMER
/32
f
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
(@ 8MHz
)
f
OSC
WATCHDOG
WATCHDOG RESET
LTIC
46/122
1
LTICR
8-bit
INPUT CAPTURE
REGISTER
8
LTCSR
WDG
TBF TBIETBICFICIE
RF
LTTB INTERRUPT REQUEST
LTIC INTERRUPT REQUEST
WDGDWDGE
07
Page 47
LITE TIMER (Cont’d)
11.1.3 Functional Description
The value of the 8-bit counter cannot be rea d 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 regul ar intervals to
prevent a watchdog reset occurring. Refer to Fig-
ure 31.
If the watchdog is not enabled immediately after
reset, the first watchdog timeout will be shorter
than 2ms, because this period is counted s tarting
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 enabl e
the Watchdog immediately after reset or else to
set the WDGD bit before the WGDE bit so a
watchdo g res et w ill no t occ ur fo r at lea s t 2ms.
Note: Software can use the timebase feature to
set the WDGD bit at 1 or 2 ms intervals.
ST7LITE0, ST7SUPERLITE
A Watchdog reset can be forced at any time by
setting the WDGRF bit. To generate a forced
watchdog reset, first watchdog has to be activated
by setting the WDGE bit and the n 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 , th e HALT instr ucti on sto ps t he oscill ator. When the oscilla tor is s topped, t he Lite Tim er
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 recei ved, 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.
47/122
1
Page 48
ST7LITE0, ST7SU PERLITE
Figure 31. Watchdog Timing Diagram
t
WDG
f
WDG
(2ms @ 8MHz f
OSC
HARDWARE CLEARS
WDGD BIT
)
WDGD BIT
INTERNAL
WATCHDOG
RESET
SOFTWARE SETS
WDGD BIT
WATCHDOG RESET
48/122
1
Page 49
LITE TIMER (Cont’d)
ST7LITE0, ST7SUPERLITE
Input Capt ure
The 8-bit input capture register is used to latch the
free-running upcounter after a rising or falling edge
is detected on the I CAP1 pin. W hen an input capture occurs, the ICF bit is set and the LTICR register contains the MSB of the free-running upcounter. An interrupt is generated if the ICI E bit is
set. The ICF bit is cleared by reading the LTIC R
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
OSC
/32)
by f
WAITNo effect on Lite timer
Figure 32. Input Capture Timing Diagram.
ACTIVE-HALT No effect on Lite timer
HALTLite timer stops counting
11.1.5 Interrupts
Interrupt
Event
Timebase
Event
IC EventICFICIEYesNoNo
Event
Flag
TBFTBIEYesNoYe s
Enable
Control
Bit
Exit
from
Wait
Exit
from
Halt
Exit
from
Active-
Halt
Note: Th e TBF and ICF interrupt events are con-
nected to separate interrupt vectors (see Interrupts chapter).
They generate an interrupt if the enable bit is set in
the LTCSR register and the interrupt mask in t he
CC register is reset (RIM instruction).
f
CPU
f
/32
OSC
LTIC PIN
ICF FLAG
LTICRREGISTER
4µs
(@ 8MHz f
)
OSC
02h03h05h06h07h
xxh
04h8-bit COUNTERt01h
04h
CLEARED
BY S/W
READING
LTIC REGISTER
07h
49/122
1
Page 50
ST7LITE0, ST7SU PERLITE
LITE TIMER (Cont’d)
11.1.6 Register Description
LITE TIMER CONTROL/STATUS REGISTER
(LTCSR)
Read / Write
Reset Value: 0x00 0000 (x0h)
70
ICIEICFTBTBIETBF 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
ICR7ICR6ICR5ICR4 ICR3ICR2ICR1ICR0
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 fa lling edge occurs on
the LTIC pin.
TBIE
0
ICR4
0
TBF0WDGRF0WDGE0WDGD
0
ICR3
0
ICR2
0
ICR1
0
ICR0
0
50/122
1
Page 51
11.2 12-BIT AUTORELOAD TIMER (AT)
ST7LITE0, ST7SUPERLITE
11.2.1 Introduction
The 12-bit Autoreload Tim er can be used for g eneral-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 regist er
(ATR)
■ Maskable overflow interrupt
Figure 33. 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
PWM GENERATION
f
PWM
OP0 bit
POLARITY
OE0 bit
PWM0
OUTPUT CONTROL
51/122
1
Page 52
ST7LITE0, ST7SU PERLITE
12-BIT AUTORELOAD TIMER (Cont’d)
11.2.3 Functional Description
PWM Mo de
This mode allows a Pulse Width Modulated signals to be generated on the PWM0 output pin with
minimum core processing o verhead. 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 55).
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 oc curs (OVF event),
the ATR value is loaded in the upcounter, the
preloaded Duty cycle value is transferred to the
Duty Cycle register and the PW M0 signal is se t to
a high level. When the upcounter matches the
DCRx value the PWM0 signals is set to a low level.
To obtain a signa l o n t he PWM0 pin, t he contents
of the DCR0 register must be greater than th e contents of the ATR register.
The polarity bit can be used to invert the output
signal.
The maximum available resolution for t he 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 chan ging 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 O VF event, in order no t to
miss a compare event and to have the right signal
applied on the PWM output.
Figure 34. PWM Funct ion
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
52/122
t
1
Page 53
12-BIT AUTORELOAD TIMER (Cont’d)
Figure 35. PWM Signal Example
f
COUNTER
ST7LITE0, ST7SUPERLITE
ATR= FFDh
PWM0 OUTPUT
AND OP0=0
WITH OE0=1
COUNTER
DCR0=FFEh
FFDhFFEhFFFhFFDhFFEhFFFhFFDhFFEh
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 reg isters,
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 DCR x 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 locke d until DCR0L is
written.
11.2.4 Low Power Modes
Mode Description
SLOW
The input frequency is divided
by 32
WAITNo effect on AT timer
ACTIVE-HALT
AT timer halted except if CK0=1,
CK1=0 and OVFIE =1
HALTAT timer halted
11.2.5 Interrupts
Interrupt
Event
Overflow
Event
CMP EventCMPFx CMP IE YesNoNo
Event
1)
Enable
Control
Flag
OVFOVFIEYesNoYes
Bit
Exit
from
Wait
Exit
from
Halt
Exit
from
Active-
Halt
2)
Note 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).
Note 2: only if CK0=1and CK1=0
53/122
1
Page 54
ST7LITE0, ST7SU PERLITE
12-BIT AUTORELOAD TIMER (Cont’d)
11.2.6 Register Description
TIMER CONTROL STATUS REGISTER (ATC-
This bit is read/write by software and clear by
hardware after a reset. It allows to mask the interrupt generation when CMPF bit is set.
0: CMPF interrupt disabled
1: CMPF interrupt enabled
.
Bit 7:5 = Reserved, must be kept cleared.
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. The change becomes effective after an overflow.
Counter Clock SelectionCK1CK0
OFF00
(1 ms timebase @ 8 MHz) 01
f
LTIMER
Bit 2 = OVF
f
CPU
Reserved11
Overflow Flag.
10
This bit is set by hardware and cleared by software
by reading the ATCSR register. It indicates the
transition of the counter from FFh 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) .
Bit 1 = OVFIE
Overflow Interrupt Enable.
This bit is read/write by software and cleared by
hardware after a reset.
COUNTER REGISTER HIGH (CNTRH)
Read only
Reset Value: 0000 0000 (00h)
158
0000CN11CN10CN9CN8
COUNTER REGISTER LOW (CNTRL)
Read only
Reset Value: 0000 0000 (00h)
70
CN7CN6CN5CN4CN3CN2CN1CN0
Bits 15:12 = Reserved, must be kept cleared.
Bits 11:0 = CNTR[11:0]
Counter Value
.
This 12-bit register is read by software and cleared
by hardware after a reset. The counter is incremented continuously as soon as a counter clock is
selected. To obtain the 12-bit value, software
should read the counte r value in two consec utive
read operations, LSB fi rst. When a counter overflow occurs, the counter restarts from the value
specified in the ATR register.
54/122
1
Page 55
12-BIT AUTORELOAD TIMER (Cont’d)
AUTO RELOAD REGISTER (ATRH)
Read / Write
Reset Value: 0000 0000 (00h)
ST7LITE0, ST7SUPERLITE
PWM0 DUTY CYCLE REGISTER LOW (DCR0L)
Read / Write
Reset Value: 0000 0000 (00h)
158
0000ATR11 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]
This 12-bit value is written by software. The h igh
PWMx Duty Cycle Value
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 (seeFigure 34). In Output
Compare mode, (OE0=0 in the PWMC R register)
they define the value t o be c omp ared wi th the 12-
Bits 11:0 = ATR[11:0]
Auto relo ad Regi s ter.
bit upcounter value.
This is a 12-bit register which is written by software. 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
158
0000DCR11 DCR10 DCR9 DCR8
Bit 7:2= Reserved, must be kept cleared.
Bit 1 = OP0
PWM0 Output Pola r ity.
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 register value.
0: Upcounter value does not match DCR value.
1: Upcounter value matches DCR value.
55/122
1
Page 56
ST7LITE0, ST7SU PERLITE
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
This bit is set and cleared by software.
PWM0 Output enable
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
DCR70DCR6
CN8
0
ATR6
0
0
CN7
0
ATR5
0
DCR5
0
CK1
0
CN6
0
ATR4
0
DCR4
0
CK0
0
CN11
0
CN3
0
ATR110ATR100ATR9
ATR3
0
DCR110DCR100DCR9
DCR30DCR2
OVF
0
CN10
0
CN2
0
ATR2
0
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
56/122
1
Page 57
11.3 SERIAL PERIPHE R AL IN TE R FACE ( SPI)
ST7LITE0, ST7SUPERLITE
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 how ever 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 collis ion, Master Mo de Fault and Over run
/2 max. slave mode frequency
CPU
CPU
/4 max.)
flags
Figure 36. Serial Peripheral Interface Block Diagram
Data/Address Bus
SPIDR
Read Buffer
Read
11.3.3 General Description
Figure 36 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 connect ed to external d evices 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
–SS
: Slave select:
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.
Interrupt
request
MOSI
MISO
SCK
SS
SOD
bit
8-Bit Shift Register
Write
MASTER
CONTROL
SERIAL CLOCK
GENERATOR
SPIF WCOLMODF
SPIE SPE
OVRSSISSMSOD
SPI
STATE
CONTROL
MSTR
SPR2
SPICSR
0
SS
SPICR
CPHA
SPR1CPOL
07
1
0
07
SPR0
57/122
1
Page 58
ST7LITE0, ST7SU PERLITE
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 37.
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 37. Single Master/ Single Slave Application
sponds by sending da ta to the master device via
the MISO pin. This implies full duplex communication with both data out an d 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 communicati on is possib le).
Four possible data/clock timing relationship s may
be chosen (s ee Figure 40) but m aster and slave
must be programmed with the same timing mode.
MASTER
MSBitLSBitMSBitLSBit
8-BIT SHIFT REGISTE R
SPI
CLOCK
GENERATO R
MISO
MOSI
SCK
SS
+5V
MISO
MOSI
SCK
SS
8-BIT SHIFT REGISTE R
SLAVE
Not used if SS is managed
by software
58/122
1
Page 59
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 appli c ation can c ho os e to
manage the Slave Select signal by software. This
is configured by the SSM bit in the SP I CSR register (see Figure 39)
In software management, the external SS
pin is
free for other application uses and t he i nte rnal S S
signal level is driven by writing to the SSI bit in the
SPICSR register.
In Master mode:
–SS
internal must be held high continuously
ST7LITE0, ST7SUPERLITE
In Slave Mode:
There are two cases depending on the data/clock
timing relationship (see Figure 38):
If CPHA=1 (data latched on 2nd clock edge):
internal must be held low during the entire
–SS
transmission. This implies that in s in gle 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):
internal must be held low during byte
–SS
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).
In master mode, the serial clock is output on the
SCK pin. The clock fr equen cy, polarity and phas e
are configured by software (refer to the description
of the SPICSR register).
Note: The idle s tate 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).
To operate the SPI in master mode, perform the
following two steps in order (if t he SPICSR register
is not written first, the SPICR register setting may
be not taken into account):
1. Write to the SPICSR register:
– Select the clock frequency by configuring the
SPR[2:0]bits.
– Select the clock polarity a nd clock phase by
configuring the CPOL a nd CPHA bits. Fig ur e
40 shows the four possible configurations.
Note: The slave must have the same CPOL
and CPHA settings as the master.
– Either set the SSM bit and set the SSI bit or
clear the SSM bit and tie the SS
the complete byte transmit sequence.
2. Write to the SPICR register:
– Set the MSTR and SPE bits
Note: MSTR an d SPE bits rem ain set onl y if
SS
is high).
The transmit sequence begins when software
writes a byte in the SPIDR register.
11.3.3.4 Master Mode Transmit Sequen ce
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 CC R
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.
Note: While the SPIF bit is set, all writes to the
SPIDR register are inhibited until the SPICSR register is read .
pin high for
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 regist er to perform the f ollowing actions:
– Select the clock po larity and clock phase by
configuring the CPOL and CPHA bits (see
Figure 40).
Note: T he slave must have the same CPOL
and CPHA settings as the master.
– Manage the SS
11.3.3.2 and Figure 38. If CP HA=1 SS
be held low continuously. If CPHA=0 SS
be held low during byte transmission and
pulled up between each b yte to let the slave
write in the shift register.
2. Write to the S PICR register t o clear the M STR
bit and set the SPE bit to enable the SPI I/O
functions.
11.3.3.6 Slave Mode Transmit Sequen ce
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 m ost 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 transf er is co m plete:
– 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
60/122
1
Page 61
SERIAL PERIPHERAL INTERFACE (Cont’d)
11.3.4 Clock Phase and Clock Polari ty
Four possible timing relationships may be chose n
by software, using the CPOL and CP HA bits (See
Figure 40).
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 pol arity and
CPHA (clock phase) bits selects the data capture
clock edge
Figure 40. D at a C lo ck Ti m in g D i agram
SCK
(CPOL = 1)
SCK
(CPOL = 0)
ST7LITE0, ST7SUPERLITE
Figure 40, 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 conne cted between the
master and the slave device.
Note: If CPOL is changed at the communication
byte boundaries, the SPI mus t 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 STR OB E
MSBitBit 6Bit 5
MSBitBit 6Bit 5
MSBitBit 6Bit 5
MSBitBit 6Bit 5
Bit 4Bit3Bit 2Bit 1LSBit
Bit 4Bit3Bit 2Bit 1LSBit
CPHA =0
Bit 4Bit3Bit 2Bit 1LSBit
Bit 4Bit3Bit 2Bit 1LSBit
Note:
This figure should not be used as a replacement for parametric information.
Refer to the Electrical Cha racteristics chapter.
61/122
1
Page 62
ST7LITE0, ST7SU PERLITE
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 Over run occ urs:
– The OVR bit is set and an interrupt request is
generated if the SPIE bit is set.
In this case, the rec eiver buffer contains the b yte
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 41).
Figure 41. 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
62/122
Read SPICSR
Read SPIDR
RESULT
WCOL=0
Note: Writing to the SPIDR register instead of reading it does not
reset the WCOL bit
1
Page 63
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 42).
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 42. 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 l ine
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 n ot written to its S PIDR
register.
Other transmission security methods can use
ports for handshake lines or data by tes with command fields.
ST7LITE0, ST7SUPERLITE
5V
SCK
MCU
MOSI
MOSI
SCK
Master
MCU
SS
SSSS
SCK
Slave
MOSIMOSIMOSIMISOMISOMISOMISO
MISO
Ports
Slave
MCU
SS
SCKSCK
Slave
MCU
SS
Slave
MCU
63/122
1
Page 64
ST7LITE0, ST7SU PERLITE
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 m ode through a SPIF
interrupt. The data received i s subsequently rea d
from the SPIDR register when the software is running (interrupt vector fetch). If multiple data transfers have been performed before softwa re clears
the SPIF bit, then the OVR bit is set by hardware.
Note: When waking up fr om Halt mode, if the SPI
remains in Slave mode, it is recommended to perform an extra comm unications 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 S T7 from Halt
mode only if the Slave S elect 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 ErrorOVRYesNo
Event
Flag
SPIF
MODFYesNo
Enable
Control
Bit
SPIE
Exit
from
Wait
YesYes
Exit
from
Halt
Note: The SPI interrupt events are connec ted to
the same interrupt vector (see Interrupts chapter).
They generate an interrupt if the corresponding
Enable Control Bit is set and the in terrupt mas k in
the CC register is reset (RIM instruction).
64/122
1
Page 65
ST7LITE0, ST7SUPERLITE
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 cl eared by reset, so the
SPI peripheral is not initially connected to the external pi ns.
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. Ref er to Table 15 SPI M aster
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 mus t 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 c leared by software. Used
with the SPR2 bit, they select the baud rate o f the
SPI serial clock SCK out put by the SPI in ma ster
mode.
Note: These 2 bits have no effect in slave mode.
Table 15. SPI Master mode SCK Frequency
Serial ClockSPR2SPR1SPR0
f
/4100
CPU
/8000
f
CPU
f
/16001
CPU
/32110
f
CPU
f
/64010
CPU
/128011
f
CPU
65/122
1
Page 66
ST7LITE0, ST7SU PERLITE
SERIAL PERIPHERAL INTERFACE (Cont’d)
CONTROL/STATUS REGISTER (SPICSR)
This bit is set by hardware when a trans fer 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 41).
0: No write collision occurred
1: A write collision has been detected
Bit 5 = OVR S
PI Overrun error (Read only).
This bit is set by hardware when the byte currently
being received in the shift register is ready to b e
transferred into the SPIDR register while SPIF = 1
(See Section 11.3.5.2). An interrupt is generated if
SPIE = 1 in SPICSR 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 SPICSR 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 Managem ent .
This bit is set and cleared by software. When set, it
disables the alternate funct ion 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 t he 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
D7D6D5D4D3D2D1D0
The SPIDR register is used to t ransmit 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 t he 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 SPI CSR register is
read.
Warning: A write to the SPIDR register places
data directly into the shift register f or transmission.
A read to the SPIDR register returns the value located in the buffer and not the conten t of the shift
register (see Figure 36).
pin
managed by exter-
signal con-
pin free for gener-
slave
66/122
1
Page 67
SERIAL PERIPHERAL INTERFACE (Cont’d)
Table 16. SPI Register Map and Reset Values
ST7LITE0, ST7SUPERLITE
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
67/122
1
Page 68
ST7LITE0, ST7SU PERLITE
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 vol tage
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 43.
V
and VSS are the high a nd l ow le vel reference
DD
voltage pins.
Conversion accuracy may therefore be impacted
by voltage drops a nd no ise in th e ev ent 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 b it in the AD AMP 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 switc hed 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.
Figure 43. ADC Block Diagram
f
CPU
AIN0
AIN1
AINx
DIV 2
ANALOG
MUX
0
1
7
x 1 or
x 8
AMPSEL bit
(ADCAMP Register)
3
DIV 4
R
ADC
ADCDR
1
0
(ADCAMP Reg ist er)
SLOW
bit
CH2 CH10EOC SPEEDADON0CH0
HOLD CONTROL
C
f
ADC
0
ADCCSR
ADC
ANALOG TO DIGITAL
CONVERTER
D1D3D7D6D5D4D0
D2
68/122
1
Page 69
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 t he analog i nput 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
) is greater than or equal
AIN
conversion result in the DR register is FFh (full
scale) without overflow indication.
If input voltage (V
V
(low-level voltage reference) then the con-
SSA
) is lower than or equal to
AIN
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 44:
■ Sample capacitor loading [duration: t
During this phase, the V
measured is loaded into the C
input voltage to b e
AIN
ADC
SAMPLE
]
sample
capacitor.
■ A/D conversion [duration: t
HOLD
]
During this phase, the A/D conversion is
computed (8 successive approximat ions 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
+ t
HOLD
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 pr evious measurem ent
load. The advantage of this behaviour is that it
minimizes the curre nt consum ption 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 defini-
tions and to Figure 44 for the timings.
ST7LITE0, ST7SUPERLITE
ADC Configuration
The analog input ports must be configured as input, no pull-up, no interrupt. Refer to the «I/O
ports» chapter. Using thes e pins as analog inp uts
does not affect the ability of the port to b e read as
a logic input.
In the CSR register:
– Select the CH[2:0] bits to assign t he 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 44. ADC Conversion Timings
ADON
HOLD
CONTROL
t
11.4.4 Low Power Modes
Mode Description
WAITNo effect on A/D Converter
HALT
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.
t
CONV
t
HOLD
SAMPLE
A/D Converter disabled.
After wakeup from Halt mode, the A/D Converter requires a stabilization time before accurate conversions can be performed.
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-
DATA REGISTER (ADCDAT)
Read Only
Reset Value: 0000 0000 (00h)
70
D7D6D5D4D3D2D1D0
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
This bit is set and cleared by software.
A/D Converter and Amplifier On
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
Bit 4:3 = Reserved.
Bits 2:0 = CH[2:0]
must always be cleared.
Channel Selection
These bits are set and cleared by software. They
select the analog input to convert.
Channel Pin
AIN0000
AIN1001
AIN2010
AIN3011
AIN4100
1
CH2CH1CH0
Notes:
1. The number of pins AND the channel sel ection
clock speed as shown on the table below.
f
ADC
f
/200
CPU
f
CPU
f
/41x
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.
Bit 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
70/122
1
Page 71
Table 17. ADC Register Map and Reset Values
ST7LITE0, ST7SUPERLITE
Address
(Hex.)
34h
35h
36h
Register
Label
ADCCSR
Reset Value
ADCDAT
Reset Value
ADCAMP
Reset Value
76543210
EOC0SPEED0ADON
000
D7
0
0000
D6
0
D5
0
D4
0
D3
0
SLOW0AMPSEL
CH2
0
D2
0
0
CH1
0
D1
0
00
CH0
0
D0
0
71/122
1
Page 72
ST7LITE0, ST7SU PERLITE
12 INSTRUCTIO N SET
12.1 ST7 ADDRESSING MODES
The ST7 Core features 17 different addressing
modes which can be classified in 7 main groups:
so, most of the ad dressing modes may be subdivided in two sub-modes called long and short:
– Long addressing mode is more powe rful 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.
The ST7 Instruction set is designed to minimize
the number of bytes required per instruction: To do
In Direct instructions, the operands are referenced
by their memory address.
The direct addressing m ode consists of two submodes:
Direct (short)
The address is a byte, thus requires only one byte
after the opcode, but only allows 00 - FF addressing space.
Direct (lon g)
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
sub-modes:
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 one 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 byt es 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 th e op co de. Th e i ndirect addressing mode consists of two sub-modes:
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 (lon g)
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.
73/122
1
Page 74
ST7LITE0, ST7SU PERLITE
ST7 ADDRESSING MODES (Cont’d)
12.1.6 Indire ct Indexed (S hort, 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 sub-modes:
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 Inde xed (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.
This addressing mode is used to m odify the PC
register value by adding an 8-bit signed offset to it.
Available Relative Direct/
Indirect Instructions
JRxxConditional Jump
CALLRCall Relative
Function
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 t he address follows the opcode.
Long and Short
Instructions
LDLoad
CPCompare
AND, OR, XORLogical Operations
ADC, ADD, SUB, SBC
BCPBit Compare
Short Instructions OnlyFunction
CLRClear
INC, DECIncrement/Decrement
TNZTest Negative or Zero
CPL, NEG1 or 2 Complement
BSET, BRESBit Operations
BTJT, BTJF
SLL, SRL, SRA, RLC,
RRC
Arithmetic Addition/subtraction operations
Bit Test and Jump Operations
Shift and Rotate Operations
Function
74/122
1
Page 75
12.2 INSTRUCTION GROUPS
ST7LITE0, ST7SUPERLITE
The ST7 family devices use an Instruction Set
consisting of 63 instructions. The instructions may
Load and TransferLDCLR
Stack operationPUSHPOPRSP
Increment/DecrementINCDEC
Compare and TestsCPTNZBCP
Logical operationsANDORXO RCPLNEG
Bit OperationBSETBRES
Conditional Bit Test and BranchBTJTBTJF
Arithmetic operationsADCADDSUBSBCMUL
Shift and RotatesSLLSRLSRARLCRRCSWAPSLA
Unconditional Jump or CallJRAJRTJRFJPCALLCALLRNOPRET
Conditional BranchJRxx
Interruption managementTRAPWFIHALTIRET
Condition Code Flag modificationSIMRIMSCFRCF
be subdivided into 13 main groups as illustrated in
the following table:
Using a pre-b y te
The instructions are described with one to four
bytes.
In order to extend the number of available opcodes for an 8-bit CPU (256 opcodes), three different prebyte opcodes a re defined . These prebytes
modify the meaning of the instruction they precede.
The whole instruction becomes:
PC-2 End of previous instruction
PC-1 Prebyte
PCOpcode
PC+1 Addi tional word (0 to 2) according to the
number of bytes required to compute the
effective address
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 addres sing mode . The
prebytes are:
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 usin g X indirect
indexed addressing mode by a Y one.
75/122
1
Page 76
ST7LITE0, ST7SU PERLITE
INSTRUCTION GROUPS (Cont’d)
MnemoDescriptionFunction/ExampleDstSrcHINZC
ADCAdd with CarryA = A + M + CAMHNZC
ADDAdditionA = A + MAMHNZC
ANDLogical AndA = A . MAMNZ
BCPBit compare A, Memorytst (A . M)AMNZ
BRESBit Resetbres Byte, #3M
BSETBit Setbset Byte, #3M
BTJFJump if bit is false (0)btjf Byte, #3, Jmp1MC
BTJTJump if bit is true (1)btjt Byte, #3, Jmp1MC
CALLCall subro utine
CALLRCall subroutine relative
CLRClearreg, M01
CPArithmetic Comparetst(Reg - M)regMNZC
CPLOne ComplementA = FFH-Areg, MNZ1
DECDecrementdec Yreg, MNZ
HALTHalt0
IRETInterrupt routine returnPop CC, A, X, PCHINZC
INCIncrementinc Xreg, MNZ
JPAbsolute Jumpjp [TBL.w]
JRAJump relative always
JRTJump relative
JRFNever jump jrf *
JRIHJump if ext. interrupt = 1
JRILJump if ext. interrupt = 0
JRHJump if H = 1H = 1 ?
JRNHJump if H = 0H = 0 ?
JRMJump if I = 1I = 1 ?
JRNMJump if I = 0I = 0 ?
JRMIJump if N = 1 (minus)N = 1 ?
JRPLJump if N = 0 (plus)N = 0 ?
JREQJump if Z = 1 (equal)Z = 1 ?
JRNEJump if Z = 0 (not equal)Z = 0 ?
JRCJump if C = 1C = 1 ?
JRNCJump if C = 0C = 0 ?
JRULTJump if C = 1Unsigned <
JRUGEJump if C = 0Jmp if unsigned >=
JRUGTJump if (C + Z = 0)Unsigned >
76/122
1
Page 77
ST7LITE0, ST7SUPERLITE
INSTRUCTION GROUPS (Cont’d)
MnemoDescriptionFunction/ExampleDstSrcHINZC
JRULEJump if (C + Z = 1)Unsigned <=
LDLoaddst <= srcreg, MM, regNZ
MULMultiplyX,A = X * AA, X, YX, Y, A00
NEGNegate (2’s compl)neg $10reg, MNZC
NOPNo Operation
OROR operationA = A + MAMNZ
POPPop from the Stackpop regregM
pop CCCCMHINZC
PUSHPush onto the Stackpush YMreg, CC
RCFReset carry flagC = 00
RETSubroutine Return
RIMEnable InterruptsI = 00
RLCRotate left true CC <= Dst <= Creg, MNZC
RRCRotate right true CC => Dst => Creg, MNZC
RSPReset Stack PointerS = Max allowed
SBCSubtract with CarryA = A - M - CAMNZC
SCFSet carry flagC = 11
SIMDisable InterruptsI = 11
SLAShift left ArithmeticC <= Dst <= 0reg, MNZC
SLLShift left LogicC <= Dst <= 0reg, MNZC
SRLShift right Logic0 => Dst => Creg, M0ZC
SRAShift right ArithmeticDst7 => Dst => Creg, MNZC
SUBSubtractionA = A - MAMNZC
SWAPSWAP nibblesDst[7..4] <=> Dst[3..0] reg, MNZ
TNZTest for Neg & Zerotnz lbl1NZ
TRAPS/W trapS/W interrupt1
WFIWait for Interrupt0
XORExclusive ORA = A XOR MAMNZ
77/122
1
Page 78
ST7LITE0, ST7SU PERLITE
13 ELECTRICAL CH ARACTERISTICS
13.1 PARAMETER CONDITIONS
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 t emperature, supp ly voltage an d
frequencies by tests in production on 100% of the
devices with an ambient temp erature 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 foo tnotes and are not teste d
in production. Based on characterization, the mi nimum 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
on T
=25°C, VDD=5V (for the 4.5V≤VDD≤5.5V
A
voltage range), V
voltage range) and V
2.4V≤V
≤3V voltage range). They are given only
DD
=3.75V (for the 3V≤VDD≤4.5V
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 45.
13.1.5 Pin input voltage
The input voltage measurement on a pin of the device is described in Figure 46.
Figure 46. Pin input voltage
ST7 PIN
V
IN
Figure 45. Pin loading conditions
C
L
78/122
1
ST7 PIN
Page 79
13.2 ABSOLUTE MAXIMUM RATINGS
ST7LITE0, ST7SUPERLITE
Stresses above those listed as “absolute maximum ratings” may cause permanent damage to
the device. This is a stress rating only and func tional operation of the device under these cond i-
13.2.1 Voltage Characteristics
SymbolRatingsMaximum valueUnit
- V
V
DD
V
IN
V
ESD(HBM)
V
ESD(MM)
SS
Supply voltage7.0
Input voltage on any pin
1) & 2)
Electrostatic discharge voltage (Human Body Model)
Electrostatic discharge voltage (Machine Model)
13.2.2 Current Characteristics
SymbolRatings Maximum valueUnit
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 pin25
I
IO
Output current sunk by any high sink I/O pin50
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 any other pin
2)
I
Σ
INJ(PIN)
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
reliabili ty.
VSS-0.3 to VDD+0.3
see section 13.7.2 on page 91
3)
3)
5) & 6)
5)
100
100
± 5
± 20
V
mA
SymbolRatings ValueUnit
T
STG
T
J
Storage temperature range-65 to +150°C
Maximum junction temperature (see Section 14.2 THERMAL CHARACTERISTICS)
Notes:
1. Directly connectin g the RES ET
is generated or an unexpected change of the I/O configuration occurs (for example, due to a corrupted program counter).
and I/O pins to VDD or V
could damage the dev ice if an uni ntenti onal int ernal re set
SS
To guarantee safe operation, th is connectio n has to be don e through a pull-up or pull-down r esistor (typic al: 4.7kΩ for
, 10kΩ for I/Os). Unused I/O pins must be tied in the same way to VDD or VSS according to their reset configuration.
RESET
2. When the current limitation is not possible , the V
specification. A positive injection is induced by VIN>VDD while a negative injection is induced by VIN<VSS.
I
INJ(PIN)
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
absolute m aximum rating m ust be respected, otherwis e refer to
IN
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. 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-
6. True open drain I/O port pins do not accept positive injection.
79/122
1
Page 80
ST7LITE0, ST7SU PERLITE
13.3 OPERATING CONDITIONS
13.3.1 General Operating Conditions: Suffix 6 Devices
T
= -40 to +85°C unless otherwise specified.
A
SymbolParameter ConditionsMinMaxUnit
f
= 8 MHz. max., TA = 0 to 70°C2.45.5
OSC
V
DD
f
CLKIN
Supply voltage
External clock frequency on
CLKIN pin
= 8 MHz. max.2.75.5
OSC
= 16 MHz. max.3.35.5
f
OSC
3.3V016
V
≥
DD
2.4V, T
≥
DD
2.7V
V
≥
DD
0 to +70°C
A =
08
Vf
MHzV
Figure 47. f
FUNCTIONALITY
NOT GUARANTEED
FUNCTIONALITY
GUARANTEED
AT T
CLKIN
IN THIS AREA
IN THIS AREA
0 to 70°C
A
Maximum Operating Frequency Versus V
f
[MHz]
CLKIN
16
8
4
1
0
2.02.4
2.7
3.33.54.04.55.0
Supply Voltage
DD
FUNCTIONALITY
GUARANTEED
IN THIS AREA
(UNLESS OTHERWISE
STATED IN THE
TABLES OF
PARAMET RIC DATA)
SUPPLY VOLTAGE [V]
5.5
80/122
1
Page 81
ST7LITE0, ST7SUPERLITE
13.3.2 Operating Conditions with Low Voltage Detector (LVD)
= -40 to 125°C, unless otherwise specified
T
A
SymbolParameterConditionsMin TypMax Unit
V
IT+
V
IT-
(LVD)
V
hys
Vt
POR
t
g(VDD)
I
DD(LVD
Reset release threshol d
(LVD)
(V
rise)
DD
Reset generation threshold
(V
fall)
DD
LVD voltage threshold hysteresisV
VDD rise time rate
Filtered glitch delay on V
1)
DD
)LVD/AVD current consumption200µA
High Threshold
Med. Threshold
Low Threshold
High Threshold
Med. Threshold
Low Threshold
(LVD)
-V
IT-
(LVD)
IT+
Not detected by the LVD150ns
4.00
3.40
2.65
3.80
3.20
2.40
4.25
3.60
2.90
4.05
3.40
2.70
200mV
2020000µs/V
Notes:
1. 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
= -40 to 125°C, unless otherwise specified
T
A
SymbolParameterConditionsMinTypMaxUnit
High Threshold
Med. Threshold
Low Threshold
High Threshold
Med. Threshold
Low Threshold
IT+
V
DD
-V
(AVD)
IT-
(AVD)
fallTBD0.45V
(AVD)
1=>0 AVDF flag toggle threshold
(V
rise)
DD
0=>1 AVDF flag toggle threshold
(V
fall)
DD
AVD voltage threshold hysteresisV
Voltage drop between AVD flag set
and LVD reset activation
V
IT+
V
IT-
(AVD)
V
hys
V
∆
IT-
4.40
3.90
3.20
4.30
3.70
2.90
4.70
4.10
3.40
4.60
3.90
3.20
150mV
4.50
3.80
3.15
4.30
3.65
2.90
5.00
4.30
3.60
4.90
4.10
3.40
V
V
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).
1. Data based on characterization results, not tested in production
2. RCCR1 is a factory-calibrated setting for 700kH
2% accuracy @ T
z with ±
CILLATOR ADJUSTMENT” on page 23.
3. Guaranteed by design.
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 12 on page 24.
STAB
=25°C, VDD=3V. See “INTERNAL RC OS-
A
is required to reach ACC
STAB
accuracy
PLL
83/122
1
Page 84
ST7LITE0, ST7SU PERLITE
OPERATING CONDITIONS (Cont’d)
Figure 48. 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
2.42.62.833.23.43.63.84
VDD (V)
Figure 50.
temperature @ V
(Calibrated with RCCR0: 5V @ 25°C
RC Accuracy
TypicalRC oscillator Accuracy vs
=5V
DD
2
1
0
-1
-2
-3
-4
)
(
*
-5
-4502585
(*) tested in production
(*)
Temperature (°C)
DD
(
*
@ TA=25°C
)
125
Figure 49. 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)
Figure 51. 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
2.4 2.7 3 3.3 3.75 4 4.5 5 5.5 6
Vdd (V)
DD
and RCCR Value
DD
-45°
0°
25°
90°
105°
130°
rccr=00h
rccr=64h
rccr=80h
rccr=C0h
rccr=FFh
84/122
1
Page 85
OPERATING CONDITIONS (Cont’d)
ST7LITE0, ST7SUPERLITE
Figure 52. PLL ∆f
f
∆
Max
0
Min
CPU/fCPU
CPU/fCPU
versus time
Figure 53. PLLx4 Output vs CLKIN frequency
7.00
6.00
5.00
4.00
3.00
Output Frequency (MHz)
2.00
1.00
11.522.53
Ex t ernal I n put Cl oc k Frequenc y (MHz )
3.3
3
2.7
t
w(JIT)
t
w(JIT)
Figure 54. PLLx8 Output vs CLKIN frequency
11.00
9.00
7.00
5.00
3.00
Output Frequency (MHz)
1.00
0.850.911.522.5
External Input Clock Frequency (MHz)
t
5.5
5
4.5
4
Note: f
OSC
= f
CLKIN
/2*PLL4
Note: f
OSC
= f
CLKIN
/2*PLL8
85/122
1
Page 86
ST7LITE0, ST7SU PERLITE
13.4 SUPPLY CURRENT CHARACTERISTICS
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 m ode for which the clock
is stopped).
source current consumption. To get the total de-
13.4.1 Supply Current
T
= -40 to +125°C unless otherwise specified
A
SymbolParameterConditionsTypMax Unit
≤
A
1)
2)
3)
4)
+85°C
4.507.00
1.752.70
0.751.13
0.651
0.5010
100
or VSS (no load), all peripherals
DD
CPU
mA
µ
Supply current in RUN mode
Supply current in WAIT modef
Supply current in SLOW mode f
I
DD
Supply current in SLOW WAIT mode f
Supply current in HALT mode
=5.5V
DD
V
f
=8MHz
CPU
=8MHz
CPU
=500kHz
CPU
=500kHz
CPU
-40°C≤T
+125°C5
T
=
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. SLO W mo de sele cted with f
V
(no load), all peripherals in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.
SS
4. SLO W-WAIT mod e selected with f
or VSS (no load), all peripherals in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.
V
DD
Figure 55. Typical IDD in RUN vs. f
based on f
CPU
based on f
CPU
CPU
or VSS (no load), all peripherals in reset state; clock input (CLKIN)
DD
divided by 32. Al l I/O pin s in inpu t mod e with a static v alue at VDD or
OSC
divided by 32. All I/O pins in input mode with a static val ue at
OSC
Figure 56. Typical IDD in SLOW vs. f
A
5.0
4.0
3.0
2.0
Idd (mA)
1.0
0.0
8MHz
4MHz
1MHz
2.42.73.74.555.5
Vdd (V)
Figure 57. Typical IDD in WAIT vs. f
2.0
1.5
1.0
Idd (mA)
0.5
0.0
8MHz
4MHz
1MHz
2.42.73.74.555.5
Vdd (V)
CPU
0.80
0.70
0.60
0.50
0.40
0.30
Idd (mA)
0.20
0.10
0.00
2.42.73.74.555.5
VDD (V)
Figure 58. Typical IDD in SLO W -WAI T v s . f
0.70
0.60
0.50
0.40
0.30
Idd (mA)
0.20
0.10
0.00
2.42.73.74.555.5
Vdd (V)
500kHz
250kHz
125kHz
CPU
500kHz
250kHz
125kHz
86/122
1
Page 87
SUPPLY CURRENT CHARACTERISTICS (Cont’d)
ST7LITE0, ST7SUPERLITE
Figure 59. Typical I
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
-452590130
vs. Temperature
DD
= 8MHz
CPU
Tem perature (°C)
RUN
WAIT
SLOW
SLOW WAIT
13.4.2 On-chip peripherals
SymbolParameterConditionsTypUnit
I
DD(AT)
I
DD(SPI)
I
DD(ADC)
12-bit Auto-Reload Timer supply current
SPI supply current
ADC supply current when converting
2)
3)
f
=4MHzV
1)
CPU
f
=8MHzV
CPU
f
=4MHzV
CPU
f
=8MHzV
CPU
f
=4MHz
ADC
3.0V50
=
DD
5.0V150
=
DD
3.0V50
=
DD
5.0V300
=
DD
3.0V780
=
V
DD
5.0V1100
V
=
DD
A
µ
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
cpu
=8MHz.
measurement between reset configuration and a permanent SPI master communica-
DD
measurement between reset configuration and continuous A/D conversions with am-
DD
plifier off.
87/122
1
Page 88
ST7LITE0, ST7SU PERLITE
13.5 CLOCK AND TIMING CHARACTERISTICS
Subject to general operating conditions for V
DD
, f
OSC
, and TA.
13.5.1 General Timings
SymbolParameter
t
c(INST)
t
v(IT)
Instruction cycle time f
Interrupt reaction time
t
v(IT)
= ∆t
c(INST)
+ 10
1
3)
ConditionsMin Typ
=8MHz
CPU
=8MHz
f
CPU
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. Dt
ish the current instruction execution.
is the number of t
c(INST)
2)
MaxUnit
2312t
CPU
2503751500ns
1022t
1.252.75
cycles needed to fin-
CPU
CPU
µ
s
88/122
1
Page 89
ST7LITE0, ST7SUPERLITE
13.6 MEMORY CHARACTERISTICS
T
= -40°C to 125°C, unless otherwise specified
A
13.6.1 RAM and Hardware Registers
SymbolParameter ConditionsMinTypMaxUnit
RM
Data retention mode
V
13.6.2 FLASH Program Memory
SymbolParameter ConditionsMinTypMaxUnit
V
t
t
N
DD
prog
RET
RW
I
DD
Operating voltage for Flash write/erase
Programming time for 1~32 bytes
Programming time for 1.5 kBytes
Data retention
Write erase cycles
Supply current
13.6.3 EEPROM Data Memory
1)
HALT mode (or RESET)1.6V
2.45.5
2)
4)
40 to +85°C510
T
=−
A
T
+25°C0.240.48
=
A
T
A
T
A
3)
+55°C
=
+25°C10K
=
20years
7)
Read / Write / Erase
modes
f
= 8MHz, VDD = 5.5V
CPU
2.6
6)
No Read/No Write Mode100
Power down mode / HALT00.1
V
ms
s
cycles
mA
A
µ
A
µ
SymbolParameter ConditionsMinTypMaxUnit
40 to +85°C510
T
t
N
prog
t
ret
RW
Programming time for 1~32 bytes
Data retention
Write erase cycles
4)
=−
A
TA=+55°C
T
=
A
3)
+25°C300K
20years
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.
ms
cycles
89/122
1
Page 90
ST7LITE0, ST7SU PERLITE
13.7 EMC 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 2 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
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.
SymbolParameterConditionsNeg
5V, T
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
DD
and V
DD
to induce a functional disturbance
V
=
DD
conforms to IEC 1000-4-2
5V, T
V
=
pins
DD
conforms to IEC 1000-4-4
Figure 60. EMC Recommended power supply connection
0.1µF10µF
ST7
DIGITAL NOISE
FILTERING
+25°C, f
=
A
+25°C, f
=
A
2)
V
DD
V
SS
8MHz
=
OSC
8MHz
=
OSC
ST72XXX
and VSS through
DD
1)
Pos
-0.7>1.5
-1.21.2
1)
Unit
kV
V
DD
Notes:
1. Data based on characterization results, not tested in production.
2. The suggested 10µF and 0.1µF decoupling capacitors on the power supply lines are proposed as a good price vs. EMC
performance tradeoff. They have to be put as close as possible to the device power supply pins. Other EMC recommendations are given in other sections (I/Os, RESET, OSCx pin characteristics).
90/122
1
Page 91
EMC CHARACTERISTICS (Cont’d)
13.7.2 Absolute Electrical Sensitivity
Based on three different tests (ESD, LU and DLU)
using specific measurement methods, the product
is stressed in order to determine its performance in
terms of electrical sensitivity. For more details, refer to the AN1181 ST7 application note.
13.7.2.1 Electro-Static Discharge (ESD)
Electro-Static Discharges (3 positive then 3 negative pulses separated by 1 second ) are applied to
the pins of each sample according to each pin
combination. The sample size depends of the
number of supply pins of the device (3 parts*(n+1)
supply pin). Two models are usually simulated:
Human Body Model and Machine Model. This test
conforms to the JESD 22-A114A/A1 15A standard.
See Figure 61 and the following test sequences.
Human Body Model Tes t Sequenc e
is loaded through S1 by the HV pulse gener-
– C
L
ator.
– S1 switches position from generator to R.
– A discharge from C
through R (body resistance)
L
to the ST7 occurs.
– S2 must be closed 10 to 100ms after the pulse
delivery period to ensure the ST7 is not left in
charge state. S2 must be opened at least 10ms
prior to the delivery of the next pulse.
ST7LITE0, ST7SUPERLITE
Machine Model Test Sequence
is loaded through S1 by the HV pulse gener-
– C
L
ator.
– S1 switches position from generator to ST7.
– A discharge from C
– S2 must be closed 10 to 100ms after the pulse
delivery period to ensure the ST7 is not left in
charge state. S2 must be opened at least 10ms
prior to the delivery of the next pulse.
– R (machine resistance), in series with S2, en-
sures a slow discharge of the ST7.
to the ST7 occurs.
L
Absolute Maximum Ratings
SymbolRatingsConditionsMaximum value
V
ESD(HBM)
V
ESD(MM)
Electro-static discharge voltage
(Human Body Model)
Electro-static discharge voltage
(Machine Model)
T
T
=
A
=
A
+25°C
+25°C
4000
TBD
Figure 61. Typical Equivalent ESD Circuits
S1
HIGH VOLTAGE
PULSE
GENERATOR
Notes:
1. Data based on characterization results, not tested in production.
R=1500
Ω
100pF
C
=
L
HUMAN BO DY MODELMACHINE MODEL
ST7
S2
HIGH VOLTAGE
PULSE
GENERATOR
S1
ST7
200pF
C
=
L
1)
Unit
V
R=10k~10MΩ
S2
91/122
1
Page 92
ST7LITE0, ST7SU PERLITE
EMC CHARACTERISTICS (Cont’d)
13.7.2.2 Static and Dynamic Latch-Up
■ LU: 3 complementary static tests are required
on 10 parts to assess the latch-up performance.
A supply overvoltage (applied to each power
supply pin), a current inje ction (applied to e ach
input, output and configurable I/O pin) and a
power supply switch sequence are performed
on each sample. This test conforms to the EIA/
JESD 78 IC latch-up standard. For more details,
refer to the AN1181 ST7 application note.
Electrical Sensitivities
SymbolParameterConditionsClass
LUStatic latch- up class
DLUDynamic latch-up class
Figure 62. Simplified Diagram of t he ESD Generator for DLU
■ DLU: Electro-Static Discharges (one positive
then one negative test) are applied to each pin
of 3 samples when the micro is running to
assess the latch-up performance in dynamic
mode. Power supplies are set to the typical
values, the oscillator is connected as near as
possible to the pins of the micro and the
component is put in reset mode. This test
conforms to the IEC1000-4-2 and SAEJ1752/3
standards and is described in Figure 62. For
more details, refer to the AN1181 ST7
application note.
+25°C
=
T
A
T
+85°C
=
A
5.5V, f
V
=
DD
OSC
4MHz, T
=
=
A
+25°C
1)
A
A
A
ESD
GENERATOR
RCH=50M
150pF
C
=
S
2)
Ω
RD=330
Ω
HV RELAY
DISCHARGE
RETURNCONNECTION
DISCHARGE TIP
ST7
V
DD
V
SS
Notes:
1. Class description: A Class is an STMicroelectronics internal specification. All its limits are higher than the JEDEC specifications, that m ean s whe n a devic e bel ongs to C lass A it e xceeds the JED EC s tanda rd. B Cla ss str ictly c overs all t he
JEDEC criteria (international standard).
2. Schaffner NSG435 with a pointed test finger.
92/122
1
Page 93
EMC CHARACTERISTICS (Cont’d)
13.7.3 ESD Pin Protection Strategy
To protect an integrated circuit against ElectroStatic Discharge the stress must be c ontrolled to
prevent degradation or destruction of the circuit elements. The stress generally affects the circuit elements which are conn ected to the p ads but ca n
also affect the internal devices when the supply
pads receive the stress. The elements to be protected must n ot re ce i ve exce ssive current, volt a ge
or heating within their structure.
An ESD network combines the different input and
output ESD protections. This network works, by allowing safe discharge paths for the pins subjected
to ESD stress. Two critical ESD stress cases are
presented in F igure 63 and Fi gure 64 for standard
pins.
ST7LITE0, ST7SUPERLITE
Standard Pin Protection
To protect the output structure the following elements are added:
– A diode to V
– A protection device between V
To protect the input structure the following elements are added:
– A resistor in series with the pad (1)
– A diode to V
– A protection device between V
(3a) and a diode from VSS (3b)
DD
(2a) and a diode from VSS (2b)
DD
and VSS (4)
DD
and VSS (4)
DD
Figure 63. Positive Stress on a Standard Pad vs. V
V
DD
(3a)
OUT
Main path
Path to avoid
V
SS
(3b)
Figure 64. Negative Stress on a Standard Pad vs. V
V
DD
(3a)
OUT
Main path
(3b)
SS
DD
(4)
(4)
V
DD
(2a)
IN
IN
(1)
(2b)
(2a)
(1)
(2b)
V
SS
V
DD
V
SS
V
SS
93/122
1
Page 94
ST7LITE0, ST7SU PERLITE
13.8 I/O PORT PIN CHARACTERISTICS
13.8.1 General Characteristics
Subject to general operating conditions for VDD, f
SymbolParameterConditionsMinTypMaxUnit
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 65). Data based on design simulation and/or technology
characteristics, not tested in production.
3. The R
scribed in Figure 66).
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 voltage0.3xV
IL
Input high level voltage0.7xV
IH
Schmitt trigger voltage
hys
hysteresis
I
Input leakage currentV
L
I
Static current consumption 2)Floating input mode200
S
Weak pull-up equivalent
PU
resistor
I/O pin capacitance5pF
IO
Output high to low level fall
time
Output low to high level rise
time
External interrupt pulse time
pull-up equiva lent resistor is base d on a resistive trans istor (correspondin g I
PU
1)
SS≤VIN≤VDD
3)
1)
1)
V
IN=VSS
CL=50pF
Between 10% and 90%
4)
, and TA unless otherwise specified.
OSC
DD
400mV
±1
VDD=5V50120250
V
=3V 160
DD
25
25
1t
current characte ristics de-
PU
DD
V
A
µ
k
Ω
ns
CPU
Figure 65. Two typical Applications with unused I/O Pin
V
Figure 66. Typical I
l
90
80
70
60
50
40
Ipu(uA)
30
20
10
0
22.533.5 44.555.56
Ta=140°C
Ta=95°C
Ta=25°C
Ta=-45°C
TO BE CHARACTERIZED
DD
10k
Ω
Note: only external pull-up allowed on ICCCLK pin
vs. VDD with VIN=V
PU
Vdd(V)
ST7XXX
UNUSED I/O PORT
SS
10k
UNUSED I/O PORT
Ω
ST7XXX
94/122
1
Page 95
ST7LITE0, ST7SUPERLITE
I/O PORT PIN CHARACTERISTICS (Cont’d)
13.8.2 Output Driving Current
, f
Subject to general operating conditions for V
DD
SymbolParameterConditionsMinMaxUnit
Output low level voltage for a standard I/O pin
when 8 pins are sunk at same time
(see Figure 70)
1)
V
OL
Output low level voltage for a high sink I/O pin
when 4 pins are sunk at same time
(see Figure 72)
V
OH
when 4 pins are sourced at same time
(see Figure 78)
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 69)
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
when 8 pins are sunk at same time
1)3)
V
OL
(see Figure 68)
Output low level voltage for a high sink I/O pin
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 75)
, and TA unless otherwise specified.
CPU
IIO=+5mA T
I
=+2mA T
IO
I
=+20mA,T
IO
=5V
I
=+8mA T
DD
IO
V
I
=-5mA, T
IO
=-2mAT
I
IO
IIO=+2mA T
I
=+8mA T
IO
=3.3V
I
=-2mAT
IO
DD
V
IIO=+2mA T
I
=+8mA T
IO
I
=-2mAT
=2.7V
IO
DD
V
85°C
≤
A
T
85°C
≥
A
85°C
≤
A
T
85°C
≥
A
85°C
≤
A
T
85°C
≥
A
85°C
≤
A
T
85°C
≥
A
85°C
≤
A
T
≥
A
≤
A
T
≥
A
≤
A
T
≥
A
≤
A
T
≥
A
≤
A
T
≥
A
≤
A
T
≥
A
≤
A
T
≥
A
≤
A
T
≥
A
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
85°C
V
DD
V
DD
V
DD
V
DD
V
DD
V
DD
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
. True open drain I/O pins does not have VOH.
VDD
3. Not tested in production, based on characterization results.
Figure 67. Typical VOL at VDD=2.4V (standard)Figure 68. Typical VOL at VDD=2.7V (standard)
0.70
0.60
0.50
0.40
0.30
0.20
VOL at VDD=2.4V
0.10
0.00
TO BECHARACTERIZED
0.0112
lio (mA)
-45
0°C
25°C
90°C
130°C
0.60
0.50
0.40
0.30
0.20
VOL at VDD=2.7V
0.10
0.00
0.0112
lio (mA)
-45°C
0°C
25°C
90°C
130°C
95/122
IO
1
Page 96
ST7LITE0, ST7SU PERLITE
I/O PORT PIN CHARACTERISTICS (Cont’d)
Figure 69. Typical V
0.70
0.60
0.50
0.40
0.30
VOL at VDD=3.3V
0.20
0.10
0.00
0.01123
Figure 71. Typical V
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
VOL at VDD=2.4V (HS)
0.20
0.10
0.00
678910
at VDD=3.3V (standard)Figure 70. Typical VOL at VDD=5V (standard)
OL
0.80
0.70
0.60
0.50
0.40
0.30
0.20
VOL at VDD=5V
0.10
0.00
0.0112345
Figure 73. Typical V
1.20
1.00
0.80
0.60
0.40
Vol (V) at VDD=3V (HS)
0.20
0.00
67891015
lio (mA)
at VDD=3V (high-sink)
OL
lio (mA )
lio (mA)
at VDD=2.4V (high- si nk)
OL
lio (mA)
-45°C
0°C
25°C
90°C
130°C
-45
0°C
25°C
90°C
130°C
-45°C
0°C
25°C
90°C
130°C
-45
0°C
25°C
90°C
130°C
Figure 72. Typical V
2.50
2.00
1.50
1.00
0.50
Vol (V) at VDD=5V (HS)
0.00
6789 10 15 20 25 30 35 40
96/122
1
at VDD=5V (high-sink)
OL
lio (mA)
-45
0°C
25°C
90°C
130°C
Page 97
I/O PORT PIN CHARACTERISTICS (Cont’d)
ST7LITE0, ST7SUPERLITE
Figure 74. 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
Figure 75. Typical V
1.20
1.00
0.80
0.60
0.40
VDD-VOH at VDD=2.7V
0.20
0.00
-0.01-1-2
DD-VOH
lio (mA)
DD-VOH
lio(mA)
at VDD=2.4V
at VDD=2.7V
-45°C
0°C
25°C
90°C
130°C
-45°C
0°C
25°C
90°C
130°C
Figure 76. 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
-0.01-1-2-3
Figure 77. 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
DD-VOH
lio (mA)
DD-VOH
lio (mA)
at VDD=3V
at VDD=4V
-45°C
0°C
25°C
90°C
130°C
-45°C
0°C
25°C
90°C
130°C
Figure 78. 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 BECHARACTERIZED
-0.01-1-2-3-4-5
DD-VOH
lio (mA)
at VDD=5V
-45°C
0°C
25°C
90°C
130°C
97/122
1
Page 98
ST7LITE0, ST7SU PERLITE
A
I/O PORT PIN CHARACTERISTICS (Cont’d)
Figure 79. Typical V
0.70
0.60
0.50
0.40
0.30
0.20
Vol (V) at lio=2mA
0.10
0.00
2.42.73.35
Figure 80. Typical V
0.70
0.60
0.50
0.40
0.30
0.20
0.10
VOL vs VDD (HS) at lio=8mA
0.00
2.435
vs. VDD (stand a r d I /Os )
OL
VDD (V)
vs. VDD (high-sink I/Os)
OL
VDD (V)
-45
0°C
25°C
90°C
130°C
-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
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
0.00
2.42.73.35
VDD (V)
2.435
VDD (V)
-45
0°C
25°C
90°C
130°C
-45
0°C
25°C
90°C
130°C
Figure 81. Typical V
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
VDD-VOH at lio=-5m
1.00
0.90
0.80
98/122
1
VDD
vs. V
DD
-45°C
0°C
25°C
90°C
130°C
DD-VOH
45
1.10
1.00
0.90
0.80
0.70
0.60
0.50
VDD-VOH (V) at lio=-2mA
0.40
2.42.7345
VDD (V)
-45°C
0°C
25°C
90°C
130°C
Page 99
13.9 CONTROL PIN CHARACTERISTICS
ST7LITE0, ST7SUPERLITE
13.9.1 Asynchronous RESET
= -40°C to 125°C, unless otherwise specified
T
A
Pin
SymbolParameterConditionsMinTypMaxUnit
V
V
V
V
R
t
w(RSTL)out
t
h(RSTL)in
t
g(RSTL)in
Figure 82. Typical Applicatio n wit h RESET
EXTERNAL
CIRCUIT
Input low level voltage0.3xV
IL
Input high level voltage0.7xV
IH
Schmitt trigger voltage hysteresis
hys
Output low level voltage
OL
Pull-up equivalent resistor
ON
2)
3) 1)
1)
=+5mA T
I
IO
VDD=5V
I
=+2mA T
IO
VDD=5V 204080
V
=3VTBD
DD
85°C
≤
A
T
85°C
≥
A
85°C
≤
A
T
85°C
≥
A
DD
Generated reset pulse durationInternal reset sources30
External reset pulse hold time
Filtered glitch duration
Recommended
if LVD is disabled
V
DD
USER
RESET
5)
0.01µF
0.01µF
4)
5)
6)7)8)
pin
V
DD
V
DD
4.7k
R
ON
Ω
Filter
PULSE
GENERATOR
20
DD
1V
0.5
0.2
1.0
1.2
0.4
0.5
200ns
ST72XXX
INTERNAL
RESET
WATCHD OG
LVD RESET
Required if LVD is disabled
V
V
k
Ω
s
µ
s
µ
Notes:
1. Data based on characterization results, not tested in production.
2. The I
(I/O ports and control pins) must not exceed I
3. The R
V
ILmax
current sunk must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of I
IO
pull-up equiv alent resisto r is based on a resistive tra nsistor. Spe cfied for volta ges on RESET pin betwe en
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
RESET
pin with a duration below t
h(RSTL)in
can be ignored.
5. The reset network protects the device against parasitic resets.
6. The output of the external reset circuit must have an open-drain output to drive the ST7 reset pad. Otherwise the device
can be damaged when the ST7 generates an internal reset (LVD or watchdog).
7. Whatever the reset source is (internal or external), the user must ensure that the level on the RESET
max. level specified in section 13.9. 1 on page 99. Otherwise the reset will not be taken into account internally.
the V
IL
8. Because the reset circuit is designed to allow the internal RESET to be output in the RESET
that the current sunk on the RESET
ified for I
INJ(RESET)
in section 13.2.2 on page 79.
pin (by an external pull-p for example) is less than the absolute maximum value spec-
pin, the user must ensure
pin can go below
99/122
IO
1
Page 100
ST7LITE0, ST7SU PERLITE
13.10 COMMUNICATION INTERFACE CHARACTERISTICS
13.10.1 SPI - Serial Peripheral Interface
Subject to general operating conditions for V
f
, and TA unless otherwise specified.
OSC
DD
Refer to I/O port characteristics for more details on
the input/output alternate function characteristics
,
, SCK, MOSI, MISO) .
(SS
SymbolParameterConditionsMinMaxUnit
/128
f
CPU
0.0625
0f
100
90
100
100
100
100
0.25
f
CPU
CPU
/42
/24
120
f
SCK
1/t
c(SCK)
t
r(SCK)
t
f(SCK)
t
su(SS)
t
h(SS)
t
w(SCKH)
t
w(SCKL)
t
su(MI)
t
su(SI)
t
h(MI)
t
h(SI)
t
a(SO)
t
dis(SO)
t
v(SO)
t
h(SO)
t
v(MO)
t
h(MO)
Master
=8MHz
f
SPI clock frequency
Slave
CPU
f
CPU
=8MHz
SPI clock rise and fall timesee I/O port pin description
SS setup timeSlave120
SS hold timeSlave120
SCK high and low time
Data input setup time
Data input hold time
Master
Slave
Master
Slave
Master
Slave
Data output access timeSlave0120
Data output disable timeSlave240
Data output valid time
Data output hold time0
Data output valid time
Data output hold time0.25
Slave (after enable edge)
Master (before capture edge)
MHz
ns
t
CPU
Figure 83. SPI Slave Timing Diagram with CPHA=0
SS
INPUT
INPUT
SCK
MISO
MOSI
CPHA=0
CPOL=0
CPHA=0
CPOL=1
OUTPUT
INPUT
t
su(SS)
t
a(SO)
t
su(SI)
t
w(SCKH)
t
w(SCKL)
MSB OUT
MSB IN
t
c(SCK)
t
h(SI)
t
v(SO)
3)
BIT6 OUT
BIT1 IN
t
h(SO)
t
r(SCK)
t
f(SCK)
LSB OUTseenote2
LSB IN
t
h(SS)
t
dis(SO)
see
note 2
Notes:
1. Data based on design simulation and/or characterisation results, not tested in production.
2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has
its alternate function capability released. In this case, the pin status depends on the I/O port configuration.
3. Measurement points are done at CMOS levels: 0.3xV
and 0.7xVDD.
DD
100/122
1
Loading...
+ hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.