Datasheet ST7LITE0, ST7SUPERLITE Datasheet (STMicroelectronics)

Page 1

8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY,

■ Memories

– 1K or 1.5K bytes single voltage Flash Pro-

gram memory with read-out protection, In-Circuit and In-Application Programming (ICP and IAP). 10K write/erase cycles guaranteed, data

retention: 20 years at 55°C. – 128 bytes RAM. – 128 bytes data EEPROM with read-out pro-

tection. 300K write/erase cycles guaranteed,

data retention: 20 years at 55°C.

■ Clock, Reset and Supply Management

– 3-level low voltage supervisor (LVD) and aux-

iliary voltage detector (AVD) for safe power-

on/off procedures – Clock sources: internal 1MHz RC 1% oscilla-

tor or external clock – PLL x4 or x8 for 4 or 8 MHz internal clock – Four Power Saving Modes: Halt, Active-Halt,

Wait and Slow

■ Interrupt Management

– 10 interrupt vectors plus TRAP and RESET – 4 external interrupt lines (on 4 vectors)

■ I/O Ports

– 13 multifunctional bidirectional I/O lines – 9 alternate function lines – 6 high sink outputs

■ 2 Timers

– One 8-bit Lite Timer (LT) with prescaler in-

cluding: watchdog, 1 realtime base and 1 in-

put capture. – One 12-bit Auto-reload Timer (AT) with output

Device Summary

ST7LITE0, ST7SUPERLITE

DATA EEPROM, ADC, TIMERS, SPI

DIP16

SO16

150”

compare function and PWM

■ 1 Communication Interface

– SPI synchronous serial interface

■ A/D Converter

– 8-bit resolution for 0 to V – Fixed gain Op-amp for 11-bit resolution in 0 to

250 mV range (@ 5V V

– 5 input channels

■ Instruction Set

– 8-bit data manipulation – 63 basic instructions with illegal opcode de-

tection – 17 main addressing modes – 8 x 8 unsigned multiply instruction

■ Development Tools

– Full hardware/software development package

)

Rev. 3.0

October 2004 1/124

Page 2

Table of Contents

ST7LITE0, ST7SUPERLITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3 REGISTER & MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4 FLASH PROGRAM MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.3 PROGRAMMING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.4 ICC INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.5 MEMORY PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.6 RELATED DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.7 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5 DATA EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.3 MEMORY ACCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.4 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.5 ACCESS ERROR HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.6 DATA EEPROM READ-OUT PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.7 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6 CENTRAL PROCESSING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.3 CPU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

7 SUPPLY, RESET AND CLOCK MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.1 INTERNAL RC OSCILLATOR ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.2 PHASE LOCKED LOOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.3 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

7.4 RESET SEQUENCE MANAGER (RSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

8 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

8.1 NON MASKABLE SOFTWARE INTERRUPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

8.2 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

8.3 PERIPHERAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

8.4 SYSTEM INTEGRITY MANAGEMENT (SI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

9 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

9.2 SLOW MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

9.3 WAIT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

9.4 ACTIVE-HALT AND HALT MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

10 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

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10.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

10.2 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

10.3 UNUSED I/O PINS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

10.4 LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

10.5 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

10.6 I/O PORT IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

11 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

11.1 LITE TIMER (LT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

11.2 12-BIT AUTORELOAD TIMER (AT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

11.3 SERIAL PERIPHERAL INTERFACE (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

11.4 8-BIT A/D CONVERTER (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

12 INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

12.1 ST7 ADDRESSING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

12.2 INSTRUCTION GROUPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

13 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

13.1 PARAMETER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

13.2 ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

13.3 OPERATING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

13.4 SUPPLY CURRENT CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

13.5 CLOCK AND TIMING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

13.6 MEMORY CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

13.7 EMC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

13.8 I/O PORT PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

13.9 CONTROL PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

13.10 COMMUNICATION INTERFACE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . 102

13.11 8-BIT ADC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

14 PACKAGE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

14.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

14.2 THERMAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

14.3 SOLDERING AND GLUEABILITY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

15 DEVICE CONFIGURATION AND ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . 111

15.1 OPTION BYTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

15.2 DEVICE ORDERING INFORMATION AND TRANSFER OF CUSTOMER CODE . . . . 113

15.3 DEVELOPMENT TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

15.4 ST7 APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

16 IMPORTANT NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

16.1 EXECUTION OF BTJX INSTRUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

16.2 IN-CIRCUIT PROGRAMMING OF DEVICES PREVIOUSLY PROGRAMMED WITH HARDWARE WATCHDOG OPTION 119

16.3 IN-CIRCUIT DEBUGGING WITH HARDWARE WATCHDOG . . . . . . . . . . . . . . . . . . . 119

17 SUMMARY OF CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

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Table of Contents

ERRATA SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

1 SILICON IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

2 REFERENCE SPECIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

3 SILICON limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

3.1 NEGATIVE INJECTION IMPACT ON ADC ACCURACY . . . . . . . . . . . . . . . . . . . . . . . 121

3.2 ADC CONVERSION SPURIOUS RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

3.3 FUNCTIONAL ESD SENSITIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

3.4 CLEARING ACTIVE INTERRUPTS OUTSIDE INTERRUPT ROUTINE . . . . . . . . . . . . 122

4 DEVICE MARKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

5 ERRATA SHEET REVISION History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

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1 INTRODUCTION

ST7LITE0, ST7SUPERLITE

The ST7LITE0 and ST7SUPERLITE are members of the ST7 microcontroller family. All ST7 devices are based on a common industry-standard 8-bit core, featuring an enhanced instruction set.

The 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 devices can be placed in WAIT, SLOW, or HALT mode, reducing power consumption when the application is in idle or standby state.

Figure 1. General Block Diagram

Internal CLOCK

V V

RESET

DD SS

1 MHz. RC OSC

PLL x 4 or x 8

LVD/AVD

POWER SUPPLY

CONTROL

The enhanced instruction set and addressing modes of the ST7 offer both power and flexibility to software developers, enabling the design of highly efficient and compact application code. In addition to standard 8-bit data management, all ST7 microcontrollers feature true bit manipulation, 8x8 unsigned multiplication and indirect addressing modes.

For easy reference, all parametric data are located in section 13 on page 80.

LITE TIMER

w/ WATCHDOG

PORT A

ADDRESS AND DATA BUS

12-BIT AUTO-

RELOAD TIMER

PA7:0

(8 bits)

8-BIT CORE

ALU

FLASH

MEMORY

(1 or 1.5K Bytes)

RAM

(128 Bytes)

DATA EEPROM

(128 Bytes)

SPI

PORT B

8-BIT ADC

PB4:0

(5 bits)

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ST7LITE0, ST7SUPERLITE

2 PIN DESCRIPTION

Figure 2. 16-Pin Package Pinout (150mil)

RESET

SS/AIN0/PB0

SCK/AIN1/PB1 MISO/AIN2/PB2 MOSI/AIN3/PB3

CLKIN/AIN4/PB4

1 2 3

ei3

4 5 6

ei2

7 8

ei0

ei1

PA0 (HS)/LTIC

PA1 (HS)

PA2 (HS)/ATPWM0

PA3 (HS)

PA4 (HS)

PA5 (HS)/ICCDATA

PA6/MCO/ICCCLK

PA7

(HS) 20mA high sink capability eixassociated external interrupt vector

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PIN DESCRIPTION (Cont’d) Legend / Abbreviations for Table 1:

Type: I = input, O = output, S = supply In/Output level: C= CMOS 0.15V

= CMOS 0.3VDD/0.7VDD with input trigger

/0.85VDD with input trigger

Output level: HS = 20mA high sink (on N-buffer only) Port and control configuration:

– Input: float = floating, wpu = weak pull-up, int = interrupt – Output: OD = open drain, PP = push-pull

Table 1. Device Pin Description

ST7LITE0, ST7SUPERLITE

, ana = analog

n°

1V 2V 3 RESET

4 PB0/AIN0/SS

5 PB1/AIN1/SCK I/O C

6 PB2/AIN2/MISO I/O C 7 PB3/AIN3/MOSI I/O C 8 PB4/AIN4/CLKIN I/O C

9 PA7 I/O C

10 PA6 /MCO/ICCCLK I/O C

Pin Name

SS DD

I/O C

PA5/ ICCDATA

Type

S Ground S Main power supply

I/O C

Level Port / Control

Input Output

Input

Output

float

X ei3 X X X Port B0

X XXXXPort B1

X XXXXPort B2

X ei2 X X X Port B3

X XXXXPort B4

X ei1 X X Port A7

X X XXPort A6

HS X XXXPort A5 In Circuit Communication Data

int

wpu

X X Top priority non maskable interrupt (active low)

ana

Main

Function

(after reset)

Alternate Function

ADC Analog Input 0 or SPI Slave Select (active low) Caution: No negative current injection allowed on this pin. For details, refer to section 13.2.2 on

page 81

ADC Analog Input 1 or SPI Clock Caution: No negative current injection allowed on this pin. For details, refer to section 13.2.2 on

page 81

ADC Analog Input 2 or SPI Master In/ Slave Out Data

ADC Analog Input 3 or SPI Master Out / Slave In Data

ADC Analog Input 4 or External clock input

Main Clock Output/In Circuit Communication Clock. Caution: During normal operation this pin must be pulled- up, internally or externally (external pull-up of 10k mandatory in noisy environment). This is to avoid entering ICC mode unexpectedly during a reset. In the application, even if the pin is configured as output, any reset will put it back in input pull-up

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ST7LITE0, ST7SUPERLITE

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3 REGISTER & MEMORY MAP

ST7LITE0, ST7SUPERLITE

As shown in Figure 3 and Figure 4, the MCU is capable of addressing 64K bytes of memories and I/ O registers.

The available memory locations consist of up to 128 bytes of register locations, 128 bytes of RAM, 128 bytes of data EEPROM and up to 1.5 Kbytes of user program memory. The RAM space includes up to 64 bytes for the stack from 0C0h to 0FFh.

Figure 3. Memory Map (ST7LITE0)

0000h 007Fh

0080h

00FFh

0100h

0FFFh

1000h 107Fh

1080h

HW Registers

(see Table 2)

RAM

(128 Bytes)

Reserved

Data EEPROM

(128 Bytes)

0080h

00BFh 00C0h

00FFh

The highest address bytes contain the user reset and interrupt vectors.

The size of Flash Sector 0 is configurable by Option byte.

IMPORTANT: Memory locations marked as “Reserved” must never be accessed. Accessing a reserved area can have unpredictable effects on the device.

Short Addressing RAM (zero page)

64 Bytes Stack

1000h 1001h

see section 7.1 on page 24

RCCR0 RCCR1

F9FFh FA00h

FFDFh FFE0h

FFFFh

Reserved

Flash Memory

(1.5K)

Interrupt & Reset Vectors

(see Table 6)

PROGRAM MEMORY

FA00h FBFFh

FC00h FFFFh

1.5K FLASH

0.5 Kbytes

SECTOR 1

1 Kbytes

SECTOR 0

FFDEh

RCCR0

FFDFh

RCCR1

see section 7.1 on page 24

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ST7LITE0, ST7SUPERLITE

Figure 4. Memory Map (ST7SUPERLITE)

0000h 007Fh

0080h

00FFh

0100h

FBFFh FC00h

FFDFh

FFE0h FFFFh

HW Registers

(see Table 2)

RAM

(128 Bytes)

Reserved

Flash Memory

(1K)

Interrupt & Reset Vectors

(see Table 6)

FC00h

FDFFh

FE00h FFFFh

0080h

00BFh 00C0h

00FFh

Short Addressing RAM (zero page)

64 Bytes Stack

1K FLASH

PROGRAM MEMORY

0.5 Kbytes

SECTOR 1

0.5 Kbytes

SECTOR 0

FFDEh FFDFh

see section 7.1 on page 24

RCCR0 RCCR1

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Table 2. Hardware Register Map

ST7LITE0, ST7SUPERLITE

Address Block

0000h 0001h 0002h

0003h 0004h 0005h

0006h to

000Ah 000Bh

000Ch 000Dh

000Eh 000Fh 0010h 0011h 0012h 0013h

0014h to

0016h 0017h

0018h

Port A

Port B

LITE

TIMER

AUTO-RELOAD

TIMER

AUTO-RELOAD

TIMER

Label

PADR PADDR PAOR

PBDR PBDDR PBOR

LTCSR LTICR

ATCSR CNTRH CNTRL ATRH ATRL PWMCR PWM0CSR

DCR0H DCR0L

Port A Data Register Port A Data Direction Register Port A Option Register

Port B Data Register Port B Data Direction Register Port B Option Register

Reserved area (5 bytes)

Lite Timer Control/Status Register Lite Timer Input Capture Register

Timer Control/Status Register Counter Register High Counter Register Low Auto-Reload Register High Auto-Reload Register Low PWM Output Control Register PWM 0 Control/Status Register

Reserved area (3 bytes)

PWM 0 Duty Cycle Register High PWM 0 Duty Cycle Register Low

Reset

Status

00h

00h 40h

E0h

00h 00h

xxh xxh

00h 00h 00h 00h 00h 00h 00h

00h 00h

Remarks

R/W R/W R/W

R/W R/W

R/W

R/W Read Only

R/W Read Only Read Only R/W R/W R/W R/W

R/W R/W

0019h to

002Eh 0002Fh FLASH FCSR Flash Control/Status Register 00h R/W 00030h EEPROM EECSR Data EEPROM Control/Status Register 00h R/W

0031h

0032h

0033h

0034h

0035h

0036h

0037h ITC EICR External Interrupt Control Register 00h R/W

0038h

0039h

SPI

ADC

CLOCKS

SPIDR SPICR SPICSR

ADCCSR ADCDR ADCAMP

MCCSR RCCR

SPI Data I/O Register SPI Control Register SPI Control/Status Register

A/D Control Status Register A/D Data Register A/D Amplifier Control Register

Main Clock Control/Status Register RC oscillator Control Register

Reserved area (22 bytes)

xxh 0xh 00h

00h 00h 00h

00h FFh

R/W R/W R/W

R/W Read Only R/W

R/W R/W

11/124

Page 12

ST7LITE0, ST7SUPERLITE

12/124

Page 13

4 FLASH PROGRAM MEMORY

ST7LITE0, ST7SUPERLITE

4.1 Introduction

The ST7 single voltage extended Flash (XFlash) is a non-volatile memory that can be electrically erased and programmed either on a byte-by-byte basis or up to 32 bytes in parallel.

The XFlash devices can be programmed off-board (plugged in a programming tool) or on-board using In-Circuit Programming or In-Application Programming.

The array matrix organisation allows each sector to be erased and reprogrammed without affecting other sectors.

4.2 Main Features

■ ICP (In-Circuit Programming)

■ IAP (In-Application Programming)

■ ICT (In-Circuit Testing) for downloading and

executing user application test patterns in RAM

■ Sector 0 size configurable by option byte

■ Read-out and write protection

4.3 PROGRAMMING MODES

The ST7 can be programmed in three different ways:

– Insertion in a programming tool. In this mode,

FLASH sectors 0 and 1, option byte row and data EEPROM can be programmed or erased.

– In-Circuit Programming. In this mode, FLASH

sectors 0 and 1, option byte row and data EEPROM can be programmed or erased without removing the device from the application board.

– In-Application Programming. In this mode,

sector 1 and data EEPROM can be programmed or erased without removing the device from the application board and while the application is running.

4.3.1 In-Circuit Programming (ICP)

ICP uses a protocol called ICC (In-Circuit Communication) which allows an ST7 plugged on a printed circuit board (PCB) to communicate with an external programming device connected via cable. ICP is performed in three steps:

Switch the ST7 to ICC mode (In-Circuit Communications). This is done by driving a specific signal sequence on the ICCCLK/DATA pins while the RESET pin is pulled low. When the ST7 enters ICC mode, it fetches a specific RESET vector which points to the ST7 System Memory containing the ICC protocol routine. This routine enables the ST7 to receive bytes from the ICC interface.

– Download ICP Driver code in RAM from the

ICCDATA pin

– Execute ICP Driver code in RAM to program

the FLASH memory

Depending on the ICP Driver code downloaded in RAM, FLASH memory programming can be fully customized (number of bytes to program, program locations, or selection of the serial communication interface for downloading).

4.3.2 In Application Programming (IAP)

This mode uses an IAP Driver program previously programmed in Sector 0 by the user (in ICP mode).

This mode is fully controlled by user software. This allows it to be adapted to the user application, (user-defined strategy for entering programming mode, choice of communications protocol used to fetch the data to be stored etc.) IAP mode can be used to program any memory areas except Sector 0, which is write/erase protected to allow recovery in case errors occur during the programming operation.

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Page 14

ST7LITE0, ST7SUPERLITE

FLASH PROGRAM MEMORY (Cont’d)

4.4 ICC interface

ICP needs a minimum of 4 and up to 6 pins to be connected to the programming tool. These pins are:

– RESET

–V

: device reset

: device power supply ground

– 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

al, see Note 3)

Notes:

1. If the ICCCLK or ICCDATA pins are only used as outputs in the application, no signal isolation is necessary. As soon as the Programming Tool is plugged to the board, even if an ICC session is not in progress, the ICCCLK and ICCDATA pins are not available for the application. If they are used as inputs by the application, isolation such as a serial resistor has to be implemented in case another device forces the signal. Refer to the Programming Tool documentation for recommended resistor values.

2. During the ICP session, the programming tool must control the RESET

pin. This can lead to conflicts between the programming tool and the application reset circuit if it drives more than 5mA at

Figure 5. Typical ICC Interface

high level (push pull output or pull-up resistor<1K). A schottky diode can be used to isolate the application RESET circuit in this case. When using a classical RC network with R>1K or a reset management IC with open drain output and pull-up resistor>1K, no additional components are needed. In all cases the user must ensure that no external reset is generated by the application during the ICC session.

3. The use of Pin 7 of the ICC connector depends on the Programming Tool architecture. This pin must be connected when using most ST Programming Tools (it is used to monitor the application power supply). Please refer to the Programming Tool manual.

4. Pin 9 has to be connected to the CLKIN pin of the ST7 when the clock is not available in the application or if the selected clock option is not programmed in the option byte.

Caution: During normal operation, ICCCLK pin must be pulled- up, internally or externally (external pull-up of 10k mandatory in noisy environment). This is to avoid entering ICC mode unexpectedly during a reset. In the application, even if the pin is configured as output, any reset will put it back in input pull-up.

APPLICATION POWER SUPPLY

14/124

(See Note 3)

VDD

OPTIONAL (See Note 4)

CLKIN

ST7

PROGRAMMING TOOL

ICC CONNECTOR

ICC Cable

ICC CONNECTOR

HE10 CONNECTOR TYPE

9753

1 246810

RESET

ICCCLK

ICCDATA

APPLICATION BOARD

APPLICATION RESET SOURCE

See Note 2

See Note 1 and Caution See Note 1

APPLICATION

I/O

Page 15

FLASH PROGRAM MEMORY (Cont’d)

ST7LITE0, ST7SUPERLITE

4.5 Memory Protection

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

4.5.1 Read out Protection

Readout protection, when selected provides a protection against program memory content extraction and against write access to Flash memory. Even if no protection can be considered as totally unbreakable, the feature provides a very high level of protection for a general purpose microcontroller. Both program and data E

memory are protected.

In flash devices, this protection is removed by reprogramming the option. In this case, both program and data E

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

data. Its purpose is to provide advanced security to applications and prevent any change being made to the memory content.

Warning: Once set, Write/erase protection can never be removed. A write-protected flash device is no longer reprogrammable.

Write/erase protection is enabled through the FMP_W bit in the option byte.

4.6 Related Documentation

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

4.7 Register Description

FLASH CONTROL/STATUS REGISTER (FCSR)

Read/Write Reset Value: 000 0000 (00h) 1st RASS Key: 0101 0110 (56h) 2nd RASS Key: 1010 1110 (AEh)

70 00000OPTLATPGM

Note: This register is reserved for programming using ICP, IAP or other programming methods. It controls the XFlash programming and erasing operations.

When an EPB or another programming tool is used (in socket or ICP mode), the RASS keys are sent automatically.

Table 3. FLASH Register Map and Reset Values

Address

(Hex.)

002Fh

Label

FCSR

Reset Value

76543210

00000

OPT

LAT

PGM

15/124

Page 16

ST7LITE0, ST7SUPERLITE

5 DATA EEPROM

5.1 INTRODUCTION

The Electrically Erasable Programmable Read Only Memory can be used as a non volatile backup for storing data. Using the EEPROM requires a basic access protocol described in this chapter.

Figure 6. EEPROM Block Diagram

EECSR

ADDRESS DECODER

0 E2LAT00 0 0 0 E2PGM

ROW

DECODER

5.2 MAIN FEATURES

■ Up to 32 Bytes programmed in the same cycle

■ EEPROM mono-voltage (charge pump)

■ Chained erase and programming cycles

■ Internal control of the global programming cycle

duration

■ WAIT mode management

■ Readout protection

HIGH VOLTAGE

PUMP

EEPROM

MEMORY MATRIX

(1 ROW = 32 x 8 BITS)

ADDRESS BUS

128128 4 4

DATA

MULTIPLEXER

DATA BUS

32 x 8 BITS

DATA LATCHES

16/124

Page 17

DATA EEPROM (Cont’d)

ST7LITE0, ST7SUPERLITE

5.3 MEMORY ACCESS

The Data EEPROM memory read/write access modes are controlled by the E2LAT bit of the EEPROM Control/Status register (EECSR). The flowchart in Figure 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 the EECSR register is cleared. In a read cycle, the byte to be accessed is put on the data bus in less than 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 EEPROM Programming Flowchart

READ MODE

E2LAT=0

E2PGM=0

the value is latched inside the 32 data latches according to its address.

When PGM bit is set by the software, all the previous bytes written in the data latches (up to 32) are programmed in the EEPROM cells. The effective high address (row) is determined by the last EEPROM write sequence. To avoid wrong programming, the user must take care that all the bytes written between two programming sequences have the same high address: only the five Least Significant Bits of the address can change.

At the end of the programming cycle, the PGM and LAT bits are cleared simultaneously.

Note: Care should be taken during the programming cycle. Writing to the same memory location will over-program the memory (logical AND between the two write access data result) because the data latches are only cleared at the end of the programming cycle and by the falling edge of the E2LAT bit. It is not possible to read the latched data. This note is ilustrated by the Figure 9.

WRITE MODE

E2LAT=1

E2PGM=0

READ BYTES

IN EEPROM AREA

CLEARED BY HARDWARE

WRITE UP TO 32 BYTES

(with the same 11 MSB of the address)

IN EEPROM AREA

START PROGRAMMING CYCLE

E2PGM=1 (set by software)

E2LAT=1

E2LAT

17/124

Page 18

ST7LITE0, ST7SUPERLITE

DATA EEPROM (Cont’d)

Figure 8. Data E

DEFINITION

PROM Write Operation

⇓ Row / Byte ⇒ 0 1 2 3 ... 30 31 Physical Address

ROW

...

00h...1Fh 20h...3Fh

Nx20h...Nx20h+1Fh

E2LAT bit E2PGM bit

Read operation impossible

Byte 1 Byte 2 Byte 32

PHASE 1

Writing data latches Waiting E2PGM and E2LAT to fall

Set by USER application

Programming cycle

PHASE 2

Read operation possible

Cleared by hardware

Note: If a programming cycle is interrupted (by software or a reset action), the integrity of the data in mem-

ory is not guaranteed.

18/124

Page 19

DATA EEPROM (Cont’d)

ST7LITE0, ST7SUPERLITE

5.4 POWER SAVING MODES

Wait mode

The DATA EEPROM can enter WAIT mode on execution of the WFI instruction of the microcontroller or when the microcontroller enters Active-HALT mode.The DATA EEPROM will immediately enter this mode if there is no programming in progress, otherwise the DATA EEPROM will finish the cycle and then enter WAIT mode.

Active-Halt mode

Refer to Wait mode.

Halt mode

The DATA EEPROM immediately enters HALT mode if the microcontroller executes the HALT instruction. Therefore the EEPROM will stop the function in progress, and data may be corrupted.

5.5 ACCESS ERROR HANDLING

If a read access occurs while E2LAT=1, then the data bus will not be driven.

If a write access occurs while E2LAT=0, then the data on the bus will not be latched.

If a programming cycle is interrupted (by software/ RESET action), the memory data will not be guaranteed.

5.6 Data EEPROM Read-out Protection

The read-out protection is enabled through an option bit (see section 15.1 on page 111).

When this option is selected, the programs and data stored in the EEPROM memory are protected against read-out (including a re-write protection). In Flash devices, when this protection is removed by reprogramming the Option Byte, the entire Program memory and EEPROM is first automatically erased.

Note: Both Program Memory and data EEPROM are protected using the same option bit.

Figure 9. Data EEPROM Programming Cycle

READ OPERATION NOT POSSIBLE

INTERNAL PROGRAMMING VOLTAGE

ERASE CYCLE WRITE CYCLE

WRITE OF

DATA LATCHES

PROG

READ OPERATION POSSIBLE

LAT

PGM

19/124

Page 20

ST7LITE0, ST7SUPERLITE

DATA EEPROM (Cont’d)

5.7 REGISTER DESCRIPTION

EEPROM CONTROL/STATUS REGISTER (EECSR)

Read/Write Reset Value: 0000 0000 (00h)

70 000000E2LATE2PGM

Bits 7:2 = Reserved, forced by hardware to 0. Bit 1 = E2LAT Latch Access Transfer

This bit is set by software. It is cleared by hardware at the end of the programming cycle. It can only be cleared by software if the E2PGM bit is cleared. 0: Read mode 1: Write mode

Bit 0 = E2PGM Programming control and status This bit is set by software to begin the programming cycle. At the end of the programming cycle, this bit is cleared by hardware. 0: Programming finished or not yet started 1: Programming cycle is in progress

Note: if the E2PGM bit is cleared during the programming cycle, the memory data is not guaranteed

Table 4. DATA EEPROM Register Map and Reset Values

Address

(Hex.)

0030h

Label

EECSR

Reset Value

76543210

000000

E2LAT0E2PGM

20/124

Page 21

6 CENTRAL PROCESSING UNIT

ST7LITE0, ST7SUPERLITE

6.1 INTRODUCTION

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

6.2 MAIN FEATURES

■ 63 basic instructions

■ Fast 8-bit by 8-bit multiply

■ 17 main addressing modes

■ Two 8-bit index registers

■ 16-bit stack pointer

■ Low power modes

■ Maskable hardware interrupts

■ Non-maskable software interrupt

6.3 CPU REGISTERS

The 6 CPU registers shown in Figure 10 are not present in the memory mapping and are accessed by specific instructions.

Figure 10. CPU Registers

Accumulator (A)

The Accumulator is an 8-bit general purpose register used to hold operands and the results of the arithmetic and logic calculations and to manipulate data.

Index Registers (X and Y)

In indexed addressing modes, these 8-bit registers are used to create either effective addresses or temporary storage areas for data manipulation. (The Cross-Assembler generates a precede instruction (PRE) to indicate that the following instruction refers to the Y register.)

The Y register is not affected by the interrupt automatic procedures (not pushed to and popped from the stack).

Program Counter (PC)

The program counter is a 16-bit register containing the address of the next instruction to be executed by the CPU. It is made of two 8-bit registers PCL (Program Counter Low which is the LSB) and PCH (Program Counter High which is the MSB).

ACCUMULATOR

RESET VALUE = RESET VECTOR @ FFFEh-FFFFh

1C11HINZ

X INDEX REGISTER

Y INDEX REGISTER

PROGRAM COUNTER

CONDITION CODE REGISTER

STACK POINTER

21/124

Page 22

ST7LITE0, ST7SUPERLITE

CPU REGISTERS (Cont’d)

CONDITION CODE REGISTER (CC)

Read/Write Reset Value: 111x1xxx

70 111HINZC

The 8-bit Condition Code register contains the interrupt mask and four flags representative of the result of the instruction just executed. This register can also be handled by the PUSH and POP instructions.

These bits can be individually tested and/or controlled by specific instructions.

Bit 4 = H Half carry. This bit is set by hardware when a carry occurs be-

tween bits 3 and 4 of the ALU during an ADD or ADC instruction. It is reset by hardware during the same instructions. 0: No half carry has occurred. 1: A half carry has occurred.

This bit is tested using the JRH or JRNH instruction. The H bit is useful in BCD arithmetic subroutines.

Bit 3 = I Interrupt mask. This bit is set by hardware when entering in inter-

rupt or by software to disable all interrupts except the TRAP software interrupt. This bit is cleared by software. 0: Interrupts are enabled. 1: Interrupts are disabled.

This bit is controlled by the RIM, SIM and IRET instructions and is tested by the JRM and JRNM instructions.

Note: Interrupts requested while I is set are latched and can be processed when I is cleared. By default an interrupt routine is not interruptable

because the I bit is set by hardware at the start of the routine and reset by the IRET instruction at the end of the routine. If the I bit is cleared by software in the interrupt routine, pending interrupts are serviced regardless of the priority level of the current interrupt routine.

Bit 2 = N Negative. This bit is set and cleared by hardware. It is repre-

sentative of the result sign of the last arithmetic, logical or data manipulation. It is a copy of the 7 bit of the result. 0: The result of the last operation is positive or null. 1: The result of the last operation is negative

(i.e. the most significant bit is a logic 1).

This bit is accessed by the JRMI and JRPL instructions.

Bit 1 = Z Zero. This bit is set and cleared by hardware. This bit in-

dicates that the result of the last arithmetic, logical or data manipulation is zero. 0: The result of the last operation is different from

zero.

1: The result of the last operation is zero. This bit is accessed by the JREQ and JRNE test

instructions. Bit 0 = C Carry/borrow.

This bit is set and cleared by hardware and 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.

22/124

Page 23

ST7LITE0, ST7SUPERLITE

CPU REGISTERS (Cont’d)

Stack Pointer (SP)

Read/Write Reset Value: 00 FFh

15 8

00000000 70 1 1 SP5 SP4 SP3 SP2 SP1 SP0

The Stack Pointer is a 16-bit register which is always pointing to the next free location in the stack. It is then decremented after data has been pushed onto the stack and incremented before data is popped from the stack (see Figure 11).

Since the stack is 64 bytes deep, the 10 most significant bits are forced by hardware. Following an MCU Reset, or after a Reset Stack Pointer instruction (RSP), the Stack Pointer contains its reset value (the SP5 to SP0 bits are set) which is the stack higher address.

The least significant byte of the Stack Pointer (called S) can be directly accessed by a LD instruction.

Note: When the lower limit is exceeded, the Stack Pointer wraps around to the stack upper limit, without indicating the stack overflow. The previously stored information is then overwritten and therefore lost. The stack also wraps in case of an underflow.

The stack is used to save the return address during a subroutine call and the CPU context during an interrupt. The user may also directly manipulate the stack by means of the PUSH and POP instructions. In the case of an interrupt, the PCL is stored at the first location pointed to by the SP. Then the other registers are stored in the next locations as shown in Figure 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 locations in the stack area.

Figure 11. Stack Manipulation Example

PCH

23/124

Page 24

ST7LITE0, ST7SUPERLITE

7 SUPPLY, RESET AND CLOCK MANAGEMENT

The device includes a range of utility features for securing the application in critical situations (for example in case of a power brown-out), and reducing the number of external components.

Main features

■ Clock Management

– 1 MHz internal RC oscillator (enabled by op-

tion byte) – External Clock Input (enabled by option byte) – PLL for multiplying the frequency by 4 or 8

(enabled by option byte)

■ Reset Sequence Manager (RSM)

■ System Integrity Management (SI)

– Main supply Low voltage detection (LVD) with

reset generation (enabled by option byte) – Auxiliary Voltage detector (AVD) with interrupt

capability for monitoring the main supply (en-

abled by option byte)

7.1 INTERNAL RC OSCILLATOR ADJUSTMENT

The ST7 contains an internal RC oscillator with an accuracy of 1% for a given device, temperature and voltage. It must be calibrated to obtain the frequency required in the application. This is done by software writing a calibration value in the RCCR (RC Control Register).

Whenever the microcontroller is reset, the RCCR returns to its default value (FFh), i.e. each time the device is reset, the calibration value must be loaded in the RCCR. Predefined calibration values are stored in EEPROM for 3.0 and 5V V ages at 25°C, as shown in the following table.

supply volt-

Notes:

– See “ELECTRICAL CHARACTERISTICS” on

page 80. 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 and V

pins as close as possible to the ST7 de-

vice.

ST7FLITE05/

ST7FLITES5

Address

FFDEh

FFDFh

RCCR Conditions

=5V

=25°C

RCCR0

RCCR1

=1MHz

=3.0V

=25°C

=700KHz

ST7FLITE09

Address

1000h and FFDEh

1001h andFFDFh

– These two bytes are systematically programmed

by ST, including on FASTROM devices. Consequently, customers intending to use FASTROM service must not use these two bytes.

– RCCR0 and RCCR1 calibration values will be

erased if the read-out protection bit is reset after it has been set. See “Read out Protection” on page 15.

Caution: If the voltage or temperature conditions change in the application, the frequency may need to be recalibrated.

Refer to application note AN1324 for information on how to calibrate the RC frequency using an external reference signal.

7.2 PHASE LOCKED LOOP

The PLL can be used to multiply a 1MHz frequency from the RC oscillator or the external clock by 4 or 8 to obtain f

of 4 or 8 MHz. The PLL is ena-

OSC

bled and the multiplication factor of 4 or 8 is selected by 2 option bits.

– The x4 PLL is intended for operation with V

the 2.4V to 3.3V range

– The x8 PLL is intended for operation with V

the 3.3V to 5.5V range

Refer to Section 15.1 for the option byte description.

If the PLL is disabled and the RC oscillator is enabled, then f

OSC =

1MHz.

If both the RC oscillator and the PLL are disabled,

is driven by the external clock.

OSC

24/124

Page 25

ST7LITE0, ST7SUPERLITE

Figure 12. PLL Output Frequency Timing Diagram

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 frequency, the LOCKED bit in the SICSCR register is set. Full PLL accuracy (ACC a stabilization time of t

STAB

) is reached after

PLL

(see Figure 12 and

13.3.4 Internal RC Oscillator and PLL)

Refer to section 8.4.4 on page 36 for a description of the LOCKED bit in the SICSR register.

Bit 1 = MCO Main Clock Out enable This bit is read/write by software and cleared by hardware after a reset. This bit allows to enable the MCO output clock. 0: MCO clock disabled, I/O port free for general

purpose I/O.

1: MCO clock enabled.

Bit 0 = SMS Slow Mode select This bit is read/write by software and cleared by hardware after a reset. This bit selects the input

OSC

or f

clock f 0: Normal mode (f 1: Slow mode (f

/32.

OSC

CPU = fOSC

/32)

RC CONTROL REGISTER (RCCR)

Read / Write Reset Value: 1111 1111 (FFh) 0:C

7.3 REGISTER DESCRIPTION

MAIN CLOCK CONTROL/STATUS REGISTER (MCCSR)

Read / Write Reset Value: 0000 0000 (00h)

Bits 7:2 = Reserved, must be kept cleared.

25/124

Page 26

ST7LITE0, ST7SUPERLITE

Figure 13. Clock Management Block Diagram

CLKIN

OSC

CR4CR7 CR0CR1CR2CR3CR6 CR5

Tunable

Oscillator1% RC

/2 DIVIDER

/32 DIVIDER

Option byte

8-BIT

LITE TIMER COUNTER

/32

OSC

MCO

SMS

RCCR

PLL 1MHz -> 8MHz PLL 1MHz -> 4MHz

MCCSR

1MHz

8MHz 4MHz

0 to 8 MHz

Option byte

LTIMER

(1ms timebase @ 8 MHz f

CPU

TO CPU AND PERIPHERALS

(except LITE TIMER)

OSC

CPU

OSC

)

MCO

26/124

Page 27

7.4 RESET SEQUENCE MANAGER (RSM)

ST7LITE0, ST7SUPERLITE

7.4.1 Introduction

The reset sequence manager includes three RESET sources as shown in Figure 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 sequence consists of 3 phases

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

The RESET vector fetch phase duration is 2 clock cycles.

If the PLL is enabled by option byte, it outputs the clock after an additional delay of t

STARTUP

(see

Figure 12).

Figure 14. RESET Sequence Phases

RESET

Active Phase

INTERNAL RESET

256 CLOCK CYCLES

FETCH

VECTOR

RESET

FILTER

PULSE

GENERATOR

INTERNAL RESET

WATCHDOG RESET

LVD RESET

27/124

Page 28

ST7LITE0, ST7SUPERLITE

RESET SEQUENCE MANAGER (Cont’d)

7.4.2 Asynchronous External RESET

The RESET output with integrated R

pin is both an input and an open-drain

weak pull-up resistor.

This pull-up has no fixed value but varies in accordance with the input voltage. It

can be pulled low by external circuitry to reset the device. See Electrical Characteristic section for more details.

A RESET signal originating from an external source must have a duration of at least t

h(RSTL)in

in order to be recognized (see Figure 16). This detection is asynchronous and therefore the MCU can enter reset state even in HALT mode.

The RESET

pin is an asynchronous signal which plays a major role in EMS performance. In a noisy environment, it is recommended to follow the guidelines mentioned in the electrical characteristics section.

7.4.3 External Power-On RESET

If the LVD is disabled by option byte, to start up the microcontroller correctly, the user must ensure by means of an external reset circuit that the reset signal is held low until V level specified for the selected f

is over the minimum

frequency.

OSC

Figure 16. RESET Sequences

A proper reset signal for a slow rising V

supply

can generally be provided by an external RC network connected to the RESET

pin.

7.4.4 Internal Low Voltage Detector (LVD) RESET

Two different RESET sequences caused by the internal LVD circuitry can be distinguished:

■ Power-On RESET

■ Voltage Drop RESET

The device RESET pulled low when V V

DD<VIT-

(falling edge) as shown in Figure 16.

The LVD filters spikes on V

pin acts as an output that is

DD<VIT+

(rising edge) or

larger than t

g(VDD)

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

IT+(LVD)

IT-(LVD)

EXTERNAL RESET SOURCE

RESET PIN

WATCHDOG RESET

RUN

LVD

RESET

ACTIVE PHASE

RUN

h(RSTL)in

EXTERNAL

RESET

ACTIVE PHASE

WATCHDOG UNDERFLOW

RUN RUN

INTERNALRESET (256 T VECTOR FETCH

WATCHDOG

RESET

ACTIVE

PHASE

w(RSTL)out

CPU

)

28/124

Page 29

8 INTERRUPTS

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 17. The maskable interrupts must be enabled by clearing the I bit in order to be serviced. However, disabled interrupts may be latched and processed when they are enabled (see external interrupts subsection).

Note: After reset, all interrupts are disabled. When an interrupt has to be serviced: – Normal processing is suspended at the end of

the current instruction execution.

– The PC, X, A and CC registers are saved onto

the stack.

– The I bit of the CC register is set to prevent addi-

tional interrupts.

– The PC is then loaded with the interrupt vector of

the interrupt to service and the first instruction of the interrupt service routine is fetched (refer to the Interrupt Mapping Table for vector addresses).

The interrupt service routine should finish with the IRET instruction which causes the contents of the saved registers to be recovered from the stack.

Note: As a consequence of the IRET instruction, the I bit will be cleared and the main program 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 interrupts are simultaneously pending, an hardware priority defines which one will be serviced first (see the Interrupt Mapping Table).

Interrupts and Low Power Mode

All interrupts allow the processor to leave the WAIT low power mode. Only external and specifically mentioned interrupts allow the processor to leave the HALT low power mode (refer to the “Exit from HALT“ column in the Interrupt Mapping Table).

8.1 NON MASKABLE SOFTWARE INTERRUPT

This interrupt is entered when the TRAP instruction is executed regardless of the state of the I bit. It will be serviced according to the flowchart on

Figure 17.

8.2 EXTERNAL INTERRUPTS

External interrupt vectors can be loaded into the PC register if the corresponding external interrupt occurred and if the I bit is cleared. These interrupts allow the processor to leave the Halt low power mode.

The external interrupt polarity is selected through the miscellaneous register or interrupt register (if available).

An external interrupt triggered on edge will be latched and the interrupt request automatically cleared upon entering the interrupt service routine.

Caution: The type of sensitivity defined in the Miscellaneous or Interrupt register (if available) applies to the ei source.

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

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

– Access to the status register while the flag is set

followed by a read or write of an associated register.

Note: the clearing sequence resets the internal latch. A pending interrupt (i.e. waiting for being enabled) will therefore be lost if the clear sequence is executed.

29/124

Page 30

ST7LITE0, ST7SUPERLITE

INTERRUPTS (Cont’d)

Figure 17. Interrupt Processing Flowchart

FROM RESET

INTERRUPT

PENDING?

STACK PC, X, A, CC

SET I BIT

LOAD PC FROM INTERRUPT VECTOR

EXECUTE INSTRUCTION

RESTORE PC, X, A, CC FROM STACK

I BIT SET?

FETCH NEXT INSTRUCTION

THIS CLEARS I BIT BY DEFAULT

IRET?

Table 6. Interrupt Mapping

Exit from

HALT

Address

Vector

yes FFFEh-FFFFh

FFF8h-FFF9h

yes

N°

Source

Block

Description

RESET Reset

TRAP Software Interrupt no FFFCh-FFFDh

Label

Priority

Order

Highest

Priority

0 Not used FFFAh-FFFBh 1 ei0 External Interrupt 0

N/A 2 ei1 External Interrupt 1 FFF6h-FFF7h 3 ei2 External Interrupt 2 FFF4h-FFF5h 4 ei3 External Interrupt 3 FFF2h-FFF3h 5 Not used FFF0h-FFF1h 6 Not used FFEEh-FFEFh 7 SI AVD interrupt SICSR no FFECh-FFEDh 8

AT TIMER

9 AT TIMER Overflow Interrupt ATCSR yes FFE8h-FFE9h

LITE TIMER

11 LITE TIMER RTC Interrupt LTCSR yes FFE4h-FFE5h 12 SPI SPI Peripheral Interrupts SPICSR yes FFE2h-FFE3h 13 Not used FFE0h-FFE1h

AT TIMER Output Compare Interrupt PWM0CSR no FFEAh-FFEBh LITE TIMER Input Capture Interrupt LTCSR no FFE6h-FFE7h

Lowest Priority

30/124

Page 31

INTERRUPTS (Cont’d)

ST7LITE0, ST7SUPERLITE

EXTERNAL INTERRUPT CONTROL REGISTER (EICR)

Read/Write Reset Value: 0000 0000 (00h)

IS31 IS30 IS21 IS20 IS11 IS10 IS01 IS00

Bit 7:6 = IS3[1:0] ei3 sensitivity These bits define the interrupt sensitivity for ei3 (Port B0) according to Table 7.

Bit 5:4 = IS2[1:0] ei2 sensitivity These bits define the interrupt sensitivity for ei2

Bit 1:0 = IS0[1:0] ei0 sensitivity These bits define the interrupt sensitivity for ei0 (Port A0) according to Table 7.

Note: These 8 bits can be written only when the I bit in the CC register is set.

Table 7. Interrupt Sensitivity Bits

ISx1 ISx0 External Interrupt Sensitivity

0 0 Falling edge & low level 0 1 Rising edge only 1 0 Falling edge only 1 1 Rising and falling edge

(Port B3) according to Table 7. Bit 3:2 = IS1[1:0] ei1 sensitivity

These bits define the interrupt sensitivity for ei1 (Port A7) according to Table 7.

31/124

Page 32

ST7LITE0, ST7SUPERLITE

8.4 SYSTEM INTEGRITY MANAGEMENT (SI)

The System Integrity Management block contains the Low voltage Detector (LVD) and Auxiliary Voltage Detector (AVD) functions. It is managed by the SICSR register.

Note: A reset can also be triggered following the detection of an illegal opcode or prebyte code. Refer to section 12.2.1 on page 77 for further details.

8.4.1 Low Voltage Detector (LVD)

The Low Voltage Detector function (LVD) generates a static reset when the V below a V

IT-(LVD)

reference value. This means that

supply voltage is

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 –V

IT+(LVD) IT-(LVD)

when VDD is rising

when VDD is falling The LVD function is illustrated in Figure 18. The voltage threshold can be configured by option

byte to be low, medium or high. See section 15.1

on page 111.

Provided the minimum V the oscillator frequency) is above V

value (guaranteed for

IT-(LVD)

, the

MCU can only be in two modes:

– under full software control – in static safe reset

In these conditions, secure operation is always ensured for the application without the need for external reset hardware.

During a Low Voltage Detector Reset, the RESET pin is held low, thus permitting the MCU to reset other devices.

Notes: The LVD is an optional function which can be se-

lected by option byte. See section 15.1 on page

111.

It allows the device to be used without any external RESET circuitry.

If the LVD is disabled, an external circuitry must be used to ensure a proper power-on reset.

It is recommended to make sure that the V

supply voltage rises monotonously when the device is exiting from Reset, to ensure the application functions properly.

Caution: If an LVD reset occurs after a watchdog reset has occurred, the LVD will take priority and will clear the watchdog flag.

Figure 18. Low Voltage Detector vs Reset

IT+

(LVD)

IT-

(LVD)

RESET

32/124

hys

Page 33

Figure 19. Reset and Supply Management Block Diagram

ST7LITE0, ST7SUPERLITE

RESET

RESET SEQUENCE

MANAGER

(RSM)

WATCHDOG

TIMER (WDG)

STATUS FLAG

SYSTEM INTEGRITY MANAGEMENT

SICSR

LOC

LOW VOLTAGE

DETECTOR

AUXILIARY VOLTAGE

DETECTOR

KED

(LVD)

(AVD)

RF IE

AVD Interrupt Request

AVDAVDLVD

33/124

Page 34

ST7LITE0, ST7SUPERLITE

SYSTEM INTEGRITY MANAGEMENT (Cont’d)

8.4.2 Auxiliary Voltage Detector (AVD)

The Voltage Detector function (AVD) is based on an analog comparison between a V V

IT+(AVD)

ply voltage (V

reference value and the VDD main sup-

). The V

AVD

IT-(AVD)

for falling voltage is lower than the V

IT-(AVD)

reference value

IT+(AVD)

ence value for rising voltage in order to avoid parasitic detection (hysteresis).

The output of the AVD comparator is directly readable by the application software through a real time status bit (AVDF) in the SICSR register. This bit is read only.

Caution: The AVD functions only if the LVD is enabled through the option byte.

and

refer-

8.4.2.1 Monitoring the V

Main Supply

The AVD voltage threshold value is relative to the selected LVD threshold configured by option byte (see section 15.1 on page 111).

If the AVD interrupt is enabled, an interrupt is generated when the voltage crosses the V V

IT-(AVD)

threshold (AVDF bit is set).

IT+(LVD)

In the case of a drop in voltage, the AVD interrupt acts as an early warning, allowing software to shut down safely before the LVD resets the microcontroller. See Figure 20.

The interrupt on the rising edge is used to inform the application that the V

warning state is over

Figure 20. Using the AVD to Monitor V

IT+(AVD)

IT-(AVD)

IT+(LVD)

IT-(LVD)

AVDF bit AVD INTERRUPT

REQUEST IF AVDIE bit = 1

LVD RESET

INTERRUPT Cleared by

Early Warning Interrupt

(Power has dropped, MCU not not yet in reset)

hyst

RESET

reset

INTERRUPT Cleared by

hardware

34/124

Page 35

SYSTEM INTEGRITY MANAGEMENT (Cont’d)

8.4.3 Low Power Modes

Mode Description

WAIT HALT

No effect on SI. AVD interrupts cause the device to exit from Wait mode.

The SICSR register is frozen. The AVD remains active but the AVD interrupt cannot be used to exit from Halt mode.

8.4.3.1 Interrupts

The AVD interrupt event generates an interrupt if the corresponding Enable Control Bit (AVDIE) is

ST7LITE0, ST7SUPERLITE

set and the interrupt mask in the CC register is reset (RIM instruction).

Flag

Enable

Control

Bit

Interrupt Event

AVD event AVDF AVDIE Yes No

Event

Exit from Wait

Exit

from

Halt

35/124

Page 36

ST7LITE0, ST7SUPERLITE

SYSTEM INTEGRITY MANAGEMENT (Cont’d)

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

Read/Write Reset Value: 0000 0x00 (0xh)

70 0000

LOCK

LVDRF AVDF AVDIE

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 = LVDRF LVD reset flag This bit indicates that the last Reset was generated by the LVD block. It is set by hardware (LVD reset) and cleared by software (writing zero). See WDGRF flag description in Section 11.1 for more details. When the LVD is disabled by OPTION BYTE, the LVDRF bit value is undefined.

If the AVDIE bit is set, an interrupt request is generated when the AVDF bit is set. Refer to Figure

20 for additional details

over AVD threshold

0: V

under AVD threshold

1: V

Bit 0 = AVDIE Voltage Detector interrupt enable This bit is set and cleared by software. It enables an interrupt to be generated when the AVDF flag is set. The pending interrupt information is automatically cleared when software enters the AVD interrupt routine. 0: AVD interrupt disabled 1: AVD interrupt enabled

Application notes

The LVDRF flag is not cleared when another RESET type occurs (external or watchdog), the LVDRF flag remains set to keep trace of the original failure. In this case, a watchdog reset can be detected by software while an external reset can not.

Bit 1 = AVDF Voltage Detector flag This read-only bit is set and cleared by hardware.

Table 8. System Integrity Register Map and Reset Values

Address

(Hex.)

003Ah

Label

SICSR

Reset Value

76543210

0000

LOCKED0LVDRFxAVDF0AVDIE

36/124

Page 37

9 POWER SAVING MODES

ST7LITE0, ST7SUPERLITE

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), ACTIVE HALT and HALT.

After a RESET the normal operating mode is selected by default (RUN mode). This mode drives the device (CPU and embedded peripherals) by means of a master clock which is based on the main oscillator frequency (f

OSC

From RUN mode, the different power saving modes may be selected by setting the relevant register bits or by calling the specific ST7 software instruction whose action depends on the oscillator status.

Figure 21. Power Saving Mode Transitions

High

RUN

SLOW

9.2 SLOW MODE

This mode has two targets: – To reduce power consumption by decreasing the

internal clock in the device,

– To adapt the internal clock frequency (f

CPU

) to

the available supply voltage.

SLOW mode is controlled by the SMS bit in the MCCSR register which enables or disables Slow mode.

In this mode, the oscillator frequency is divided by

32. The CPU and peripherals are clocked at this lower frequency.

Notes: SLOW-WAIT mode is activated when entering

WAIT mode while the device is already in SLOW mode.

SLOW mode has no effect on the Lite Timer which is already clocked at F

OSC/32

Figure 22. SLOW Mode Clock Transition

/32 f

OSC

CPU

OSC

WAIT

SLOW WAIT

ACTIVE HALT

HALT

Low

POWER CONSUMPTION

SMS

OSC

NORMAL RUN MODE

REQUEST

37/124

Page 38

ST7LITE0, ST7SUPERLITE

POWER SAVING MODES (Cont’d)

9.3 WAIT MODE

WAIT mode places the MCU in a low power consumption mode by stopping the CPU. This power saving mode is selected by calling the ‘WFI’ instruction. All peripherals remain active. During WAIT mode, the I bit of the CC register is cleared, to enable all interrupts. All other registers and memory remain unchanged. The MCU remains in WAIT mode until an interrupt or RESET occurs, whereupon the Program Counter branches to the starting address of the interrupt or Reset service routine. The MCU will remain in WAIT mode until a Reset or an Interrupt occurs, causing it to wake up.

Refer to Figure 23.

Figure 23. WAIT Mode Flow-chart

OSCILLATOR

WFI INSTRUCTION

INTERRUPT

PERIPHERALS CPU

IBIT

RESET

OSCILLATOR PERIPHERALS CPU

IBIT

256 CPU CLOCK CYCLE

DELAY

OSCILLATOR PERIPHERALS CPU

IBIT

ON ON

OFF

ON ON ON

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.

38/124

Page 39

POWER SAVING MODES (Cont’d)

ST7LITE0, ST7SUPERLITE

9.4 ACTIVE-HALT AND HALT MODES

ACTIVE-HALT and HALT modes are the two lowest power consumption modes of the MCU. They are both entered by executing the ‘HALT’ instruction. The decision to enter either in ACTIVE-HALT or HALT mode is given by the LTCSR/ATCSR register status as shown in the following table:.

LTCSR

TBIE bit

ATCSR

OVFIE

0xx0 00xx 0111 1xxx x101

bit

ATCSR CK1 bit

ATCSR

CK0 bit

ACTIVE-HALT mode disabled

ACTIVE-HALT mode enabled

Meaning

9.4.1 ACTIVE-HALT MODE

ACTIVE-HALT mode is the lowest power consumption mode of the MCU with a real time clock available. It is entered by executing the ‘HALT’ instruction when active halt mode is enabled.

The MCU can exit ACTIVE-HALT mode on reception of a Lite Timer / AT Timer interrupt or a RESET.

– When exiting ACTIVE-HALT mode by means of

a RESET, a 256 CPU cycle delay occurs. After the start up delay, the CPU resumes operation by fetching the reset vector which woke it up (see

Figure 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 instruction while the Watchdog is active does not generate a RESET if the WDGHALT bit is reset. This means that the device cannot spend more than a defined delay in this power saving mode.

Figure 24. ACTIVE-HALT Timing Overview

ACTIVE

HALTRUN RUN

HALT

INSTRUCTION

[Active Halt Enabled]

256 CPU

CYCLE DELAY

RESET

INTERRUPT

FETCH

VECTOR

Figure 25. ACTIVE-HALT Mode Flow-chart

HALT INSTRUCTION

(Active Halt enabled)

INTERRUPT

OSCILLATOR PERIPHERALS CPU

IBIT

RESET

OSCILLATOR PERIPHERALS CPU

IBIT

256 CPU CLOCK CYCLE

DELAY

OSCILLATOR PERIPHERALS CPU

IBITS

FETCH RESET VECTOR

OR SERVICE INTERRUPT

ON OFF OFF

ON OFF

Notes:

1. This delay occurs only if the MCU exits ACTIVE-

HALT mode by means of a RESET.

2. Peripherals clocked with an external clock source can still be active.

3. Only the Lite Timer RTC and AT Timer interrupts can exit the MCU from ACTIVE-HALT mode.

4. Before servicing an interrupt, the CC register is pushed on the stack. The I bit of the CC register is set during the interrupt routine and cleared when the CC register is popped.

39/124

Page 40

ST7LITE0, ST7SUPERLITE

POWER SAVING MODES (Cont’d)

9.4.2 HALT MODE

The HALT mode is the lowest power consumption mode of the MCU. It is entered by executing the ‘HALT’ instruction when active halt mode is disabled.

The MCU can exit HALT mode on reception of either a specific interrupt (see Table6, “Interrupt Mapping,” on page 30) or a RESET. When exiting HALT mode by means of a RESET or an interrupt, the oscillator is immediately turned on and the 256 CPU cycle delay is used to stabilize the oscillator. After the start up delay, the CPU resumes operation by servicing the interrupt or by fetching the reset vector which woke it up (see Figure 27).

When entering HALT mode, the I bit in the CC register is forced to 0 to enable interrupts. Therefore, if an interrupt is pending, the MCU wakes immediately.

In HALT mode, the main oscillator is turned off causing all internal processing to be stopped, including the operation of the on-chip peripherals. All peripherals are not clocked except the ones which get their clock supply from another clock generator (such as an external or auxiliary oscillator).

The compatibility of Watchdog operation with HALT mode is configured by the “WDGHALT” option bit of the option byte. The HALT instruction when executed while the Watchdog system is enabled, can generate a Watchdog RESET (see sec-

tion 15.1 on page 111 for more details).

Figure 26. HALT Timing Overview

Figure 27. HALT Mode Flow-chart

HALT INSTRUCTION

(Active Halt disabled)

WDGHALT

WATCHDOG

RESET

INTERRUPT

ENABLE

OSCILLATOR PERIPHERALS CPU

IBIT

OSCILLATOR PERIPHERALS CPU

IBIT

256 CPU CLOCK CYCLE

OSCILLATOR PERIPHERALS CPU

IBITS

WATCHDOG

RESET

DELAY

DISABLE

OFF

OFF OFF

ON OFF

HALTRUN RUN

HALT

INSTRUCTION

[Active Halt disabled]

40/124

256 CPU CYCLE

DELAY

RESET

INTERRUPT

FETCH

VECTOR

FETCH RESET VECTOR

OR SERVICE INTERRUPT

Notes:

1. WDGHALT is an option bit. See option byte sec-

tion for more details.

2. Peripheral clocked with an external clock source can still be active.

3. Only some specific interrupts can exit the MCU from HALT mode (such as external interrupt). Refer to Table 6, “Interrupt Mapping,” on page 30 for more details.

4. Before servicing an interrupt, the CC register is pushed on the stack. The I bit of the CC register is set during the interrupt routine and cleared when the CC register is popped.

5. If the PLL is enabled by option byte, it outputs the clock after a delay of t

STARTUP

(see Figure 12).

Page 41

POWER SAVING MODES (Cont’d)

9.4.2.1 HALT Mode Recommendations

– Make sure that an external event is available to

wake up the microcontroller from Halt mode.

– When using an external interrupt to wake up the

microcontroller, reinitialize the corresponding I/O as “Input Pull-up with Interrupt” before executing the HALT instruction. The main reason for this is that the I/O may be wrongly configured due to external interference or by an unforeseen logical condition.

– For the same reason, reinitialize the level sensi-

tiveness of each external interrupt as a precautionary measure.

ST7LITE0, ST7SUPERLITE

– 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).

41/124

Page 42

ST7LITE0, ST7SUPERLITE

10 I/O PORTS

10.1 INTRODUCTION

The I/O ports offer different functional modes: – transfer of data through digital inputs and outputs

and for specific pins: – external interrupt generation – alternate signal input/output for the on-chip pe-

ripherals.

An I/O port contains up to 8 pins. Each pin can be programmed independently as digital input (with or without interrupt generation) or digital output.

10.2 FUNCTIONAL DESCRIPTION

Each port has 2 main registers: – Data Register (DR) – Data Direction Register (DDR) and one optional register: – Option Register (OR) Each I/O pin may be programmed using the corre-

sponding register bits in the DDR and OR registers: bit X corresponding to pin X of the port. The same correspondence is used for the DR register.

The following description takes into account the OR register, (for specific ports which do not provide this register refer to the I/O Port Implementation section). The generic I/O block diagram is shown in Figure 28

10.2.1 Input Modes

The input configuration is selected by clearing the corresponding DDR register bit.

In this case, reading the DR register returns the digital value applied to the external I/O pin.

Different input modes can be selected by software through the OR register.

Note: Writing the DR register modifies the latch value but does not affect the pin status.

External interrupt function

When an I/O is configured as Input with Interrupt, an event on this I/O can generate an external interrupt request to the CPU.

Each pin can independently generate an interrupt request. The interrupt sensitivity is independently programmable using the sensitivity bits in the EICR register.

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 selected by setting the corresponding DDR register bit. In this case, writing the DR register applies this digital value to the I/O pin through the latch. Then reading the DR register returns the previously stored value.

Two different output modes can be selected by software through the OR register: Output push-pull and open-drain.

DR register value and output pin status:

DR Push-pull Open-drain

0V 1V

SS DD

Vss

Floating

Note: When switching from input to output mode, the DR register has to be written first to drive the correct level on the pin as soon as the port is configured as an output.

10.2.3 Alternate Functions

When an on-chip peripheral is configured to use a pin, the alternate function is automatically selected. This alternate function takes priority over the standard I/O programming under the following conditions:

– When the signal is coming from an on-chip pe-

ripheral, the I/O pin is automatically configured in output mode (push-pull or open drain according to the peripheral).

– When the signal is going to an on-chip peripher-

al, the I/O pin must be configured in floating input mode. In this case, the pin state is also digitally

readable by addressing the DR register. Notes: – Input pull-up configuration can cause unexpect-

ed value at the input of the alternate peripheral

input. – When an on-chip peripheral use a pin as input

and output, this pin has to be configured in input

floating mode.

42/124

Page 43

I/O PORTS (Cont’d)

Figure 28. I/O Port General Block Diagram

ST7LITE0, ST7SUPERLITE

DATA BUS

DDR SEL

DDR

OR SEL

DR SEL

ALTERNATE OUTPUT

ALTERNATE ENABLE

If implemented

1 0

PULL-UP CONDITION

N-BUFFER

CMOS SCHMITT TRIGGER

P-BUFFER (see table below)

PULL-UP (see table below)

PAD

DIODES (see table below)

ANALOG

INPUT

EXTERNAL INTERRUPT SOURCE (eix)

POLARITY SELECTION

Table 9. I/O Port Mode Options

Configuration Mode Pull-Up P-Buffer

Input Output

Floating with/without Interrupt Off Pull-up with/without Interrupt On Push-pull Open Drain (logic level) Off

Legend: NI - not implemented

Off - implemented not activated On - implemented and activated

FROM OTHER BITS

Off

Off On

ALTERNATE

Diodes

to V

On On

INPUT

to V

43/124

Page 44

ST7LITE0, ST7SUPERLITE

I/O PORTS (Cont’d)

Table 10. I/O Port Configurations

Hardware Configuration

INPUT

OPEN-DRAIN OUTPUT

PAD

PULL-UP CONDITION

FROM

OTHER

PINS

INTERRUPT CONDITION

DR REGISTER ACCESS

ENABLE OUTPUT

W R

ALTERNATE INPUT EXTERNAL INTERRUPT

SOURCE (eix)

POLARITY

SELECTION

ANALOG INPUT

DR REGISTER ACCESS

ALTERNATEALTERNATE

DATA B U S

R/W

DATA B U S

DR REGISTER ACCESS

ALTERNATEALTERNATE

R/W

DATA B U S

PUSH-PULL OUTPUT

PAD

ENABLE OUTPUT

Notes:

1. When the I/O port is in input configuration and the associated alternate function is enabled as an output, reading the DR register will read the alternate function output status.

2. When the I/O port is in output configuration and the associated alternate function is enabled as an input, the alternate function reads the pin status given by the DR register content.

44/124

Page 45

I/O PORTS (Cont’d) CAUTION: The alternate function must not be ac-

tivated as long as the pin is configured as input with interrupt, in order to avoid generating spurious interrupts.

Analog alternate function

When the pin is used as an ADC input, the I/O must be configured as floating input. The analog multiplexer (controlled by the ADC registers) switches the analog voltage present on the selected pin to the common analog rail which is connected to the ADC input.

It is recommended not to change the voltage level or loading on any port pin while conversion is in progress. Furthermore it is recommended not to have clocking pins located close to a selected analog pin.

WARNING: The analog input voltage level must be within the limits stated in the absolute maximum ratings.

10.3 UNUSED I/O PINS

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

10.4 LOW POWER MODES

Mode Description

WAIT HALT

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

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

ST7LITE0, ST7SUPERLITE

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

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 state 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.

Figure 29. Interrupt I/O Port State Transitions

INPUT

floating/pull-up

interrupt

INPUT

floating

(reset state)

OUTPUT

open-drain

Exit

from

Wait

Yes Yes

Exit

from

Halt

OUTPUT push-pull

Table 11. Port Configuration

Port Pin name

PA7 floating

Port A

Port B

PA6:1 floating pull-up open drain push-pull PA0 floating PB4 floating pull-up open drain push-pull PB3 floating pull-up interrupt open drain push-pull PB2:1 floating pull-up open drain push-pull PB0 floating pull-up interrupt open drain push-pull

= DDR, OR

The I/O port register configurations are summarised as follows.

Input (DDR=0) Output (DDR=1)

OR = 0 OR = 1 OR = 0 OR = 1

pull-up interrupt pull-up interrupt

open drain push-pull open drain push-pull

45/124

Page 46

ST7LITE0, ST7SUPERLITE

I/O PORTS (Cont’d)

Table 12. I/O Port Register Map and Reset Values

Address

(Hex.)

0000h 0001h 0002h 0003h 0004h 0005h

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

46/124

Page 47

11 ON-CHIP PERIPHERALS

11.1 LITE TIMER (LT)

ST7LITE0, ST7SUPERLITE

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

LTIMER

/32

OSC

8-bit UPCOUNTER

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

WDG

Timebase 1 or 2 ms

(@ 8MHz f

)

OSC

WATCHDOG

WATCHDOG RESET

LTIC

LTICR

8-bit

INPUT CAPTURE

LTCSR

WDG

TBF TBIETBICFICIE

LTTB INTERRUPT REQUEST

LTIC INTERRUPT REQUEST

WDGDWDGE

47/124

Page 48

ST7LITE0, ST7SUPERLITE

LITE TIMER (Cont’d)

11.1.3 Functional Description

The value of the 8-bit counter cannot be read or written by software. After an MCU reset, it starts incrementing from 0 at a frequency of f 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.

OSC

To prevent this watchdog reset occuring, software must set the WDGD bit. The WDGD bit is cleared by hardware after t

. This means that software

WDG

must write to the WDGD bit at regular intervals to prevent a watchdog reset occurring. Refer to Fig-

ure 31.

If the watchdog is not enabled immediately after reset, the first watchdog timeout will be shorter than 2ms, because this period is counted starting from reset. Moreover, if a 2ms period has already elapsed after the last MCU reset, the watchdog reset will take place as soon as the WDGE bit is set. For these reasons, it is recommended to enable the Watchdog immediately after reset or else to set the WDGD bit before the WGDE bit so a watchdog reset will not occur for at least 2ms.

Note: Software can use the timebase feature to set the WDGD bit at 1 or 2 ms intervals.

OSC

/32. A

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 then the WDGRF bit has to be set.

The WDGRF bit also acts as a flag, indicating that the Watchdog was the source of the reset. It is automatically cleared after it has been read.

Caution: When the WDGRF bit is set, software must clear it, otherwise the next time the watchdog is enabled (by hardware or software), the microcontroller will be immediately reset.

Hardware Watchdog Option

If Hardware Watchdog is selected by option byte, the watchdog is always active and the WDGE bit in the LTCSR is not used.

Refer to the Option Byte description in the "device configuration and ordering information" section.

Using Halt Mode with the Watchdog (option)

If the Watchdog reset on HALT option is not selected by option byte, the Halt mode can be used when the watchdog is enabled.

In this case, the HALT instruction stops the oscillator. When the oscillator is stopped, the Lite Timer stops counting and is no longer able to generate a Watchdog reset until the microcontroller receives an external interrupt or a reset.

If an external interrupt is received, the WDG restarts counting after 256 CPU clocks. If a reset is generated, the Watchdog is disabled (reset state).

If Halt mode with Watchdog is enabled by option byte (No watchdog reset on HALT instruction), it is recommended before executing the HALT instruction to refresh the WDG counter, to avoid an unexpected WDG reset immediately after waking up the microcontroller.

48/124

Page 49

Figure 31. Watchdog Timing Diagram

WDG

(2ms @ 8MHz f

HARDWARE CLEARS WDGD BIT

)

OSC

ST7LITE0, ST7SUPERLITE

WDGD BIT

INTERNAL WATCHDOG RESET

SOFTWARE SETS

WDGD BIT

WATCHDOG RESET

49/124

Page 50

ST7LITE0, ST7SUPERLITE

50/124

Page 51

ST7LITE0, ST7SUPERLITE

LITE TIMER (Cont’d)

11.1.6 Register Description

LITE TIMER CONTROL/STATUS REGISTER (LTCSR)

Read / Write Reset Value: 0x00 0000 (x0h)

ICIE ICF TB TBIE TBF WDGR WDGE WDGD

Bit 7 = ICIE Interrupt Enable. This bit is set and cleared by software. 0: Input Capture (IC) interrupt disabled 1: Input Capture (IC) interrupt enabled

Bit 6 = ICF Input Capture Flag. This bit is set by hardware and cleared by software by reading the LTICR register. Writing to this bit does not change the bit value. 0: No input capture 1: An input capture has occurred

Note: After an MCU reset, software must initialise the ICF bit by reading the LTICR register

0: No counter overflow 1: A counter overflow has occurred

Bit 2 = WDGRF Force Reset/ Reset Status Flag This bit is used in two ways: it is set by software to force a watchdog reset. It is set by hardware when a watchdog reset occurs and cleared by hardware or by software. It is cleared by hardware only when an LVD reset occurs. It can be cleared by software after a read access to the LTCSR register. 0: No watchdog reset occurred. 1: Force a watchdog reset (write), or, a watchdog

reset occurred (read).

Bit 1 = WDGE Watchdog Enable This bit is set and cleared by software. 0: Watchdog disabled 1: Watchdog enabled

Bit 0 = WDGD Watchdog Reset Delay This bit is set by software. It is cleared by hardware at the end of each t

WDG

0: Watchdog reset not delayed 1: Watchdog reset delayed

period.

Bit 5 = TB Timebase period selection. This bit is set and cleared by software. 0: Timebase period = t 1: Timebase period = t

* 8000 (1ms @ 8 MHz)

OSC

* 16000 (2ms @ 8

OSC

MHz)

Bit 4 = TBIE Timebase Interrupt enable. This bit is set and cleared by software. 0: Timebase (TB) interrupt disabled 1: Timebase (TB) interrupt enabled

Bit 3 = TBF Timebase Interrupt Flag. This bit is set by hardware and cleared by software reading the LTCSR register. Writing to this bit has no effect.

Table 13. Lite Timer Register Map and Reset Values

Address

(Hex.)

0B 0C

Label

LTCSR

Reset Value

LTICR

Reset Value

76543210

ICIE

ICR7

ICF

ICR6

ICR5

LITE TIMER INPUT CAPTURE REGISTER (LTICR)

Read only Reset Value: 0000 0000 (00h)

ICR7 ICR6 ICR5 ICR4 ICR3 ICR2 ICR1 ICR0

Bit 7:0 = ICR[7:0] Input Capture Value These bits are read by software and cleared by hardware after a reset. If the ICF bit in the LTCSR is cleared, the value of the 8-bit up-counter will be captured when a rising or falling edge occurs on the LTIC pin.

TBIE

ICR4

TBF0WDGRF0WDGE0WDGD

ICR3

ICR2

ICR1

ICR0

51/124

Page 52

ST7LITE0, ST7SUPERLITE

11.2 12-BIT AUTORELOAD TIMER (AT)

11.2.1 Introduction

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

11.2.2 Main Features

■ 12-bit upcounter with 12-bit autoreload register

(ATR)

■ Maskable overflow interrupt

Figure 33. Block Diagram

ATCSR

LTIMER

(1 ms timebase @ 8MHz)

CPU

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

CMPF0 bit

COMP-

PARE

PWM

PWM GENERATION

OP0 bit

POLARITY

OE0 bit

PWM0

OUTPUT CONTROL

52/124

Page 53

12-BIT AUTORELOAD TIMER (Cont’d)

11.2.3 Functional Description PWM Mode

This mode allows a Pulse Width Modulated signals to be generated on the PWM0 output pin with minimum core processing overhead. The PWM0 output signal can be enabled or disabled using the OE0 bit in the PWMCR register. When this bit is set the PWM I/O pin is configured as output pushpull alternate function.

Note: CMPF0 is available in PWM mode (see PWM0CSR description on page 56).

PWM Frequency and Duty Cycle

The PWM signal frequency (f

) is controlled by

PWM

the counter period and the ATR register value.

= f

PWM

COUNTER

Following the above formula, if f maximum value of f

/ (4096 - ATR)

is 8 MHz, the

is 4 Mhz (ATR register

PWM

CPU

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.

ST7LITE0, ST7SUPERLITE

When a upcounter overflow occurs (OVF event), the ATR value is loaded in the upcounter, the preloaded Duty cycle value is transferred to the Duty Cycle register and the PWM0 signal is set to a high level. When the upcounter matches the DCRx value the PWM0 signals is set to a low level. To obtain a signal on the PWM0 pin, the contents of the DCR0 register must be greater than the contents of the ATR register.

The polarity bit can be used to invert the output signal.

The maximum available resolution for the PWM0 duty cycle is:

Resolution = 1 / (4096 - ATR)

Note: To get the maximum resolution (1/4096), the ATR register must be 0. With this maximum resolution and assuming that DCR=ATR, a 0% or 100% duty cycle can be obtained by changing the polarity .

Caution: As soon as the DCR0H is written, the compare function is disabled and will start only when the DCR0L value is written. If the DCR0H write occurs just before the compare event, the signal on the PWM output may not be set to a low level. In this case, the DCRx register should be updated just after an OVF event. If the DCR and ATR values are close, then the DCRx register shouldbe updated just before an OVF event, in order not to miss a compare event and to have the right signal applied on the PWM output.

Figure 34. PWM Function

4095

DUTY CYCLE

(DCR0)

AUTO-RELOAD

COUNTER

(ATR)

000

WITH OE0=1 AND OP0=0

WITH OE0=1 AND OP0=1

PWM0 OUTPUT

53/124

Page 54

ST7LITE0, ST7SUPERLITE

12-BIT AUTORELOAD TIMER (Cont’d)

Figure 35. PWM Signal Example

COUNTER

ATR= FFDh

PWM0 OUTPUT

AND OP0=0

WITH OE0=1

COUNTER

DCR0=FFEh

FFDh FFEh FFFh FFDh FFEh FFFh FFDh FFEh

Output Compare Mode

To use this function, the OE bit must be 0, otherwise the compare is done with the shadow register instead of the DCRx register. Software must then write a 12-bit value in the DCR0H and DCR0L registers. This value will be loaded immediately (without waiting for an OVF event).

The DCR0H must be written first, the output compare function starts only when the DCR0L value is written.

When the 12-bit upcounter (CNTR) reaches the value stored in the DCR0H and DCR0L registers, the CMPF0 bit in the PWM0CSR register is set and an interrupt request is generated if the CMPIE bit is set.

Note: The output compare function is only available for DCRx values other than 0 (reset value).

Caution: At each OVF event, the DCRx value is written in a shadow register, even if the DCR0L value has not yet been written (in this case, the shadow register will contain the new DCR0H value and the old DCR0L value), then:

– If OE=1 (PWM mode): the compare is done be-

tween the timer counter and the shadow register (and not DCRx)

– if OE=0 (OCMP mode): the compare is done be-

tween the timer counter and DCRx. There is no PWM signal.

The compare between DCRx or the shadow register and the timer counter is locked until DCR0L is written.

11.2.4 Low Power Modes

Mode Description

SLOW

The input frequency is divided by 32

WAIT No effect on AT timer ACTIVE-HALT

AT timer halted except if CK0=1, CK1=0 and OVFIE=1

HALT AT timer halted

11.2.5 Interrupts

Interrupt

Event

Overflow Event

CMP Event CMPFx CMPIE Yes No No

Event

Enable

Control

Flag

OVF OVFIE Yes No Yes

Bit

Exit from Wait

Exit

from

Halt

Exit

from

Active-

Halt

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

54/124

Page 55

ST7LITE0, ST7SUPERLITE

12-BIT AUTORELOAD TIMER (Cont’d)

11.2.6 Register Description

TIMER CONTROL STATUS REGISTER (ATCSR)

Read / Write Reset Value: 0000 0000 (00h)

70 0 0 0 CK1 CK0 OVF OVFIE CMPIE

0: OVF interrupt disabled 1: OVF interrupt enabled

Bit 0 = CMPIE Compare Interrupt Enable. 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.

Counter Clock Selection CK1 CK0

OFF 0 0

(1 ms timebase @ 8 MHz) 0 1

LTIMER

CPU

Reserved 1 1

Bit 2 = OVF Overflow Flag. This bit is set by hardware and cleared by software by reading the ATCSR register. It indicates the transition of the counter from FFFh to ATR value. 0: No counter overflow occurred 1: Counter overflow occurred

Caution:

When set, the OVF bit stays high for 1 f

COUNTER

cycle, (up to 1ms depending on the clock selection).

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)

15 8

0 0 0 0 CN11 CN10 CN9 CN8

COUNTER REGISTER LOW (CNTRL)

Read only Reset Value: 0000 0000 (00h)

CN7 CN6 CN5 CN4 CN3 CN2 CN1 CN0

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 counter value in two consecutive read operations, LSB first. When a counter overflow occurs, the counter restarts from the value specified in the ATR register.

55/124

Page 56

ST7LITE0, ST7SUPERLITE

12-BIT AUTORELOAD TIMER (Cont’d)

AUTO RELOAD REGISTER (ATRH)

Read / Write Reset Value: 0000 0000 (00h)

PWM0 DUTY CYCLE REGISTER LOW (DCR0L) Read / Write Reset Value: 0000 0000 (00h)

15 8

0 0 0 0 ATR11 ATR10 ATR9 ATR8

AUTO RELOAD REGISTER (ATRL)

DCR7 DCR6 DCR5 DCR4 DCR3 DCR2 DCR1 DCR0

Bits 15:12 = Reserved, must be kept cleared. Read / Write Reset Value: 0000 0000 (00h)

Bits 11:0 = DCR[11:0] PWMx Duty Cycle Value

This 12-bit value is written by software. The high

ATR7 ATR6 ATR5 ATR4 ATR3 ATR2 ATR1 ATR0

In PWM mode (OE0=1 in the PWMCR register)

the DCR[11:0] bits define the duty cycle of the Bits 15:12 = Reserved, must be kept cleared.

PWM0 output signal (see Figure 34). In Output

Compare mode, (OE0=0 in the PWMCR register)

they define the value to be compared with the 12Bits 11:0 = ATR[11:0] Autoreload Register.

bit upcounter value. This is a 12-bit register which is written by soft-

ware. The ATR register value is automatically loaded into the upcounter when an overflow occurs. The register value is used to set the PWM frequency.

PWM0 CONTROL/STATUS REGISTER

(PWM0CSR)

Read / Write

Reset Value: 0000 0000 (00h) PWM0 DUTY CYCLE REGISTER HIGH (DCR0H)

Read / Write Reset Value: 0000 0000 (00h)

000000OP0CMPF0

15 8

0 0 0 0 DCR11 DCR10 DCR9 DCR8

56/124

Bit 7:2= Reserved, must be kept cleared.

Bit 1 = OP0 PWM0 Output Polarity.

This bit is read/write by software and cleared by

hardware after a reset. This bit selects the polarity

of the PWM0 signal.

0: The PWM0 signal is not inverted.

1: The PWM0 signal is inverted.

Bit 0 = CMPF0 PWM0 Compare Flag.

This bit is set by hardware and cleared by software

by reading the PWM0CSR register. It indicates

that the upcounter value matches the DCR0 regis-

ter value.

0: Upcounter value does not match DCR value.

1: Upcounter value matches DCR value.

Page 57

12-BIT AUTORELOAD TIMER (Cont’d)

ST7LITE0, ST7SUPERLITE

PWM OUTPUT CONTROL REGISTER (PWMCR)

Bits 7:1 = Reserved, must be kept cleared. Read/Write Reset Value: 0000 0000 (00h)

Bit 0 = OE0 PWM0 Output enable.

This bit is set and cleared by software.

0: PWM0 output Alternate Function disabled (I/O

0000000OE0

pin free for general purpose I/O)

1: PWM0 output enabled

Table 14. Register Map and Reset Values

Address

(Hex.)

0D 0E 0F 10 11 12 13 17 18

Label

ATCSR

Reset Value

CNTRH

Reset Value

CNTRL

Reset Value

ATRH

Reset Value

ATRL

Reset Value

PWMCR

Reset Value

PWM0CSR

Reset Value

DCR0H

Reset Value

DCR0L

Reset Value

76543210

000 0000

CN7

0 0000

ATR7

0 0000000

000000 0000

DCR7

CN6

ATR6

DCR60DCR5

CN5

ATR5

CK1

CN4

ATR4

DCR4

CK0

CN11

CN3

ATR110ATR100ATR9

ATR3

DCR11

DCR30DCR2

OVF

CN10

CN2

ATR2

DCR100DCR90DCR8

OVFIE0CMPIE

CN9

CN1

0 0

ATR1

DCR10DCR0

CN8

CN0

ATR8

ATR0

OE0

CMPF0

0 0 0

57/124

Page 58

ST7LITE0, ST7SUPERLITE

11.3 SERIAL PERIPHERAL INTERFACE (SPI)

11.3.1 Introduction

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

11.3.2 Main Features

■ Full duplex synchronous transfers (on 3 lines)

■ Simplex synchronous transfers (on 2 lines)

■ Master or slave operation

■ Six master mode frequencies (f

■ f

■ SS Management by software or hardware

■ Programmable clock polarity and phase

■ End of transfer interrupt flag

■ Write collision, Master Mode Fault and Overrun

/2 max. slave mode frequency

CPU

/4 max.)

flags

Note: In slave mode, continuous transmission is not possible at maximum frequency due to the

Figure 36. Serial Peripheral Interface Block Diagram

Data/Address Bus

software overhead for clearing status flags and to

initiate the next transmission sequence.

11.3.3 General Description

Figure 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 connected to external devices through

3 pins:

– MISO: Master In / Slave Out data – MOSI: Master Out / Slave In data – SCK: Serial Clock out by SPI masters and in-

put by SPI slaves

: Slave select:

–SS

This input signal acts as a ‘chip select’ to let the SPI master communicate with slaves individually and to avoid contention on the data lines. Slave SS

inputs can be driven by stand-

ard I/O ports on the master MCU.

MOSI

MISO

SCK

SOD

bit

SPIDR

Read Buffer

8-Bit Shift Register

SERIAL CLOCK

Read

Write

MASTER

CONTROL

GENERATOR

Interrupt

request

SPIF WCOL MODF

SPIE SPE

OVR SSISSMSOD

SPI

STATE

CONTROL

MSTR

SPR2

CPOL

CPHA

SPICSR

1 0

SPICR

SPR1

SPR0

58/124

Page 59

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

ST7LITE0, ST7SUPERLITE

sponds by sending data to the master device via

the MISO pin. This implies full duplex communica-

tion with both data out and data in synchronized

with the same clock signal (which is provided by

the master device via the SCK pin).

To use a single data line, the MISO and MOSI pins

must be connected at each node (in this case only

simplex communication is possible).

Four possible data/clock timing relationships may

be chosen (see Figure 40) but master and slave

must be programmed with the same timing mode.

MASTER

MSBit LSBit MSBit LSBit

+5V

MISO

MOSI

SCK

8-BIT SHIFT REGISTER

SPI

CLOCK

GENERATOR

MISO

MOSI

SCK

SLAVE

Not used if SS is managed by software

59/124

Page 60

ST7LITE0, ST7SUPERLITE

SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.3.2 Slave Select Management

As an alternative to using the SS Slave Select signal, the application can choose to manage the Slave Select signal by software. This is configured by the SSM bit in the SPICSR register (see Figure 39)

In software management, the external SS free for other application uses and the internal SS signal level is driven by writing to the SSI bit in the SPICSR register.

In Master mode:

–SS

internal must be held high continuously

pin to control the

pin is

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):

–SS

internal must be held low during the entire transmission. This implies that in single slave applications the SS V

, or made free for standard I/O by manag-

ing the SS

function by software (SSM= 1 and

pin either can be tied to

SSI=0 in the in the SPICSR register)

If CPHA=0 (data latched on 1st clock edge):

–SS

internal must be held low during byte transmission and pulled high between each byte to allow the slave to write to the shift register. If SS

is not pulled high, a Write Collision error will occur when the slave writes to the shift register (see Section 11.3.5.3).

Figure 38. Generic SS

MOSI/MISO

Master SS

Slave SS

(if CPHA=0)

Slave SS

(if CPHA=1)

Timing Diagram

Byte 1 Byte 2

Figure 39. Hardware/Software Slave Select Management

SSM bit

external pin

SSI bit

SS internal

Byte 3

60/124

Page 61

SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.3.3 Master Mode Operation

In master mode, the serial clock is output on the SCK pin. The clock frequency, polarity and phase are configured by software (refer to the description of the SPICSR register).

Note: The idle state of SCK must correspond to the polarity selected in the SPICSR register (by pulling up SCK if CPOL=1 or pulling down SCK if CPOL=0).

To operate the SPI in master mode, perform the following steps in order (if the SPICSR register is not written first, the SPICR register setting (MSTR bit) may be not taken into account):

1. Write to the SPICR register: – Select the clock frequency by configuring the

SPR[2:0] bits.

– Select the clock polarity and clock phase by

configuring the CPOL and CPHA bits. Figure

40 shows the four possible configurations.

Note: The slave must have the same CPOL and CPHA settings as the master.

2. Write to the SPICSR register: – Either set the SSM bit and set the SSI bit or

clear the SSM bit and tie the SS the complete byte transmit sequence.

3. Write to the SPICR register: – Set the MSTR and SPE bits

Note: MSTR and SPE bits remain set only if SS

is high.

The transmit sequence begins when software writes a byte in the SPIDR register.

11.3.3.4 Master Mode Transmit Sequence

When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MOSI pin most significant bit first.

When data transfer is complete:

– The SPIF bit is set by hardware – An interrupt request is generated if the SPIE

bit is set and the interrupt mask in the CCR register is cleared.

Clearing the SPIF bit is performed by the following software sequence:

1.An access to the SPICSR register while the SPIF bit is set

2. A read to the SPIDR register.

pin high for

ST7LITE0, ST7SUPERLITE

Note: While the SPIF bit is set, all writes to the

SPIDR register are inhibited until the SPICSR register is read.

11.3.3.5 Slave Mode Operation

In slave mode, the serial clock is received on the SCK pin from the master device.

To operate the SPI in slave mode:

1.Write to the SPICSR register to perform the following actions:

– Select the clock polarity and clock phase by

configuring the CPOL and CPHA bits (see

Figure 40).

Note: The slave must have the same CPOL and CPHA settings as the master.

– Manage the SS

11.3.3.2 and Figure 38. If CPHA=1 SS

be held low continuously. If CPHA=0 SS be held low during byte transmission and pulled up between each byte to let the slave write in the shift register.

2.Write to the SPICR register to clear the MSTR bit and set the SPE bit to enable the SPI I/O functions.

11.3.3.6 Slave Mode Transmit Sequence

When software writes to the SPIDR register, the data byte is loaded into the 8-bit shift register and then shifted out serially to the MISO pin most significant bit first.

The transmit sequence begins when the slave device receives the clock signal and the most significant bit of the data on its MOSI pin.

When data transfer is complete:

– The SPIF bit is set by hardware – An interrupt request is generated if SPIE bit is

set and interrupt mask in the CCR register is cleared.

Clearing the SPIF bit is performed by the following software sequence:

1.An access to the SPICSR register while the SPIF bit is set.

2. A write or a read to the SPIDR register.

Notes: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read.

The SPIF bit can be cleared during a second transmission; however, it must be cleared before the second SPIF bit in order to prevent an Overrun condition (see Section 11.3.5.2).

pin as described in Section

must

61/124

Page 62

ST7LITE0, ST7SUPERLITE

SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.4 Clock Phase and Clock Polarity

Four possible timing relationships may be chosen by software, using the CPOL and CPHA bits (See

Figure 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 polarity and CPHA (clock phase) bits selects the data capture clock edge

Figure 40. Data Clock Timing Diagram

SCK (CPOL = 1)

SCK (CPOL = 0)

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 connected between the master and the slave device.

Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by resetting the SPE bit.

CPHA =1

MISO

(from master)

MOSI

(from slave)

(to slave)

CAPTURE STROBE

SCK (CPOL = 1)

SCK (CPOL = 0)

MISO

(from master)

MOSI

(from slave)

(to slave)

CAPTURE STROBE

MSBit Bit 6 Bit 5

Bit 4 Bit3 Bit 2 Bit 1 LSBit

Bit 4Bit3Bit 2Bit 1LSBit

CPHA =0

Bit 4 Bit3 Bit 2 Bit 1 LSBit

62/124

Note:

This figure should not be used as a replacement for parametric information.

Refer to the Electrical Characteristics chapter.

Page 63

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

pin pulled low.

When a Master mode fault occurs:

– The MODF bit is set and an SPI interrupt re-

quest is generated if the SPIE bit is set.

– The SPE bit is reset. This blocks all output

from the device and disables the SPI peripheral.

– The MSTR bit is reset, thus forcing the device

into slave mode.

Clearing the MODF bit is done through a software sequence:

1. A read access to the SPICSR register while the MODF bit is set.

2. A write to the SPICR register.

Notes: To avoid any conflicts in an application with multiple slaves, the SS

pin must be pulled 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

ST7LITE0, ST7SUPERLITE

not cleared the SPIF bit issued from the previously transmitted byte.

When an Overrun occurs: – The OVR bit is set and an interrupt request is

generated if the SPIE bit is set.

In this case, the receiver buffer contains the byte sent after the SPIF bit was last cleared. A read to the SPIDR register returns this byte. All other bytes are lost.

The OVR bit is cleared by reading the SPICSR register.

11.3.5.3 Write Collision Error (WCOL)

A write collision occurs when the software tries to write to the SPIDR register while a data transfer is taking place with an external device. When this happens, the transfer continues uninterrupted; and the software write will be unsuccessful.

Write collisions can occur both in master and slave mode. See also Section 11.3.3.2 Slave Select

Management.

Note: a "read collision" will never occur since the received data byte is placed in a buffer in which access is always synchronous with the MCU operation.

The WCOL bit in the SPICSR register is set if a write collision occurs.

No SPI interrupt is generated when the WCOL bit is set (the WCOL bit is a status flag only).

Clearing the WCOL bit is done through a software sequence (see Figure 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

Read SPICSR

Read SPIDR

RESULT

WCOL=0

Note: Writing to the SPIDR register instead of reading it does not reset the WCOL bit

63/124

Page 64

ST7LITE0, ST7SUPERLITE

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 line the master allows only one active slave device during a transmission.

For more security, the slave device may respond to the master with the received data byte. Then the master will receive the previous byte back from the slave device if all MISO and MOSI pins are connected and the slave has not written to its SPIDR register.

Other transmission security methods can use ports for handshake lines or data bytes with command fields.

SCK

MCU

MOSI

SCK

Master MCU

SS SS

SCK

Slave

MOSI MOSI MOSIMISO MISO MISOMISO

MISO

Ports

Slave

MCU

SCK SCK

Slave MCU

64/124

Page 65

SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.6 Low Power Modes

Mode Description

WAIT

HALT

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.

11.3.6.1 Using the SPI to wakeup the MCU from Halt mode

In slave configuration, the SPI is able to wakeup the ST7 device from HALT mode through a SPIF interrupt. The data received is subsequently read from the SPIDR register when the software is running (interrupt vector fetch). If multiple data transfers have been performed before software clears the SPIF bit, then the OVR bit is set by hardware.

Note: When waking up from Halt mode, if the SPI remains in Slave mode, it is recommended to perform an extra communications cycle to bring the SPI from Halt mode state to normal state. If the

ST7LITE0, ST7SUPERLITE

SPI exits from Slave mode, it returns to normal state immediately.

Caution: The SPI can wake up the ST7 from Halt mode only if the Slave Select signal (external SS pin or the SSI bit in the SPICSR register) is low when the ST7 enters Halt mode. So if Slave selection is configured as external (see Section

11.3.3.2), make sure the master drives a low level

on the SS

11.3.7 Interrupts

Interrupt Event

SPI End of Transfer Event

Master Mode Fault Event

Overrun Error OVR Yes No

Note: The SPI interrupt events are connected to the same interrupt vector (see Interrupts chapter). They generate an interrupt if the corresponding Enable Control Bit is set and the interrupt mask in the CC register is reset (RIM instruction).

pin when the slave enters Halt mode.

Event

Flag

SPIF

MODF Yes No

Enable

Control

Bit

SPIE

Exit from Wait

Yes Yes

Exit

from

Halt

65/124

Page 66

ST7LITE0, ST7SUPERLITE

SERIAL PERIPHERAL INTERFACE (Cont’d)

11.3.8 Register Description CONTROL REGISTER (SPICR)

Read/Write Reset Value: 0000 xxxx (0xh)

SPIE SPE SPR2 MSTR CPOL CPHA SPR1 SPR0

Bit 7 = SPIE Serial Peripheral Interrupt Enable. This bit is set and cleared by software. 0: Interrupt is inhibited 1: An SPI interrupt is generated whenever

SPIF=1, MODF=1 or OVR=1 in the SPICSR register

Bit 6 = SPE Serial Peripheral Output Enable. This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS

=0 (see Section 11.3.5.1 Master Mode Fault

(MODF)). The SPE bit is cleared by reset, so the

SPI peripheral is not initially connected to the external pins. 0: I/O pins free for general purpose I/O 1: SPI I/O pin alternate functions enabled

Bit 5 = SPR2 Divider Enable. This bit is set and cleared by software and is cleared by reset. It is used with the SPR[1:0] bits to set the baud rate. Refer to Table 15 SPI Master

mode SCK Frequency.

0: Divider by 2 enabled 1: Divider by 2 disabled

Note: This bit has no effect in slave mode. Bit 4 = MSTR Master Mode.

This bit is set and cleared by software. It is also cleared by hardware when, in master mode, SS

=0 (see Section 11.3.5.1 Master Mode Fault

(MODF)).

0: Slave mode 1: Master mode. The function of the SCK pin

changes from an input to an output and the functions of the MISO and MOSI pins are reversed.

Bit 3 = CPOL Clock Polarity. This bit is set and cleared by software. This bit determines the idle state of the serial Clock. The CPOL bit affects both the master and slave modes. 0: SCK pin has a low level idle state 1: SCK pin has a high level idle state

Note: If CPOL is changed at the communication byte boundaries, the SPI must be disabled by resetting the SPE bit.

Bit 2 = CPHA Clock Phase. This bit is set and cleared by software. 0: The first clock transition is the first data capture

edge.

1: The second clock transition is the first capture

edge.

Note: The slave must have the same CPOL and CPHA settings as the master.

Bits 1:0 = SPR[1:0] Serial Clock Frequency. These bits are set and cleared by software. Used with the SPR2 bit, they select the baud rate of the SPI serial clock SCK output by the SPI in master mode.

Note: These 2 bits have no effect in slave mode.

Table 15. SPI Master mode SCK Frequency

Serial Clock SPR2 SPR1 SPR0

/4 1 0 0

CPU

/8 0 0 0

CPU

/16 0 0 1

CPU

/32 1 1 0

CPU

/64 0 1 0

CPU

/128 0 1 1

CPU

66/124

Page 67

ST7LITE0, ST7SUPERLITE

SERIAL PERIPHERAL INTERFACE (Cont’d)

CONTROL/STATUS REGISTER (SPICSR)

Read/Write (some bits Read Only) Reset Value: 0000 0000 (00h)

SPIF WCOL OVR MODF - SOD SSM SSI

Bit 7 = SPIF Serial Peripheral Data Transfer Flag

(Read only).

This bit is set by hardware when a transfer has been completed. An interrupt is generated if SPIE=1 in the SPICR register. It is cleared by a software sequence (an access to the SPICSR register followed by a write or a read to the SPIDR register).

0: Data transfer is in progress or the flag has been

cleared.

1: Data transfer between the device and an exter-

nal device has been completed.

Note: While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read.

Bit 6 = WCOL Write Collision status (Read only). This bit is set by hardware when a write to the SPIDR register is done during a transmit sequence. It is cleared by a software sequence (see

Figure 41).

0: No write collision occurred 1: A write collision has been detected

Bit 5 = OVR SPI Overrun error (Read only). This bit is set by hardware when the byte currently being received in the shift register is ready to be transferred into the SPIDR register while SPIF = 1 (See Section 11.3.5.2). An interrupt is generated if SPIE = 1 in the SPICR register. The OVR bit is cleared by software reading the SPICSR register. 0: No overrun error 1: Overrun error detected

Bit 4 = MODF Mode Fault flag (Read only). This bit is set by hardware when the SS

pin is pulled low in master mode (see Section 11.3.5.1

Master Mode Fault (MODF)). An SPI interrupt can

be generated if SPIE=1 in the SPICR register. This bit is cleared by a software sequence (An access to the SPICSR register while MODF=1 followed by a write to the SPICR register). 0: No master mode fault detected 1: A fault in master mode has been detected

Bit 3 = Reserved, must be kept cleared. Bit 2 = SOD SPI Output Disable.

This bit is set and cleared by software. When set, it disables the alternate function of the SPI output (MOSI in master mode / MISO in slave mode) 0: SPI output enabled (if SPE=1) 1: SPI output disabled

Bit 1 = SSM SS

Management.

This bit is set and cleared by software. When set, it disables the alternate function of the SPI SS and uses the SSI bit value instead. See Section

11.3.3.2 Slave Select Management.

0: Hardware management (SS

nal pin)

1: Software management (internal SS

trolled by SSI bit. External SS al-purpose I/O)

Bit 0 = SSI SS

Internal Mode.

This bit is set and cleared by software. It acts as a ‘chip select’ by controlling the level of the SS select signal when the SSM bit is set. 0 : Slave selected 1 : Slave deselected

DATA I/O REGISTER (SPIDR)

Read/Write Reset Value: Undefined

D7 D6 D5 D4 D3 D2 D1 D0

The SPIDR register is used to transmit and receive data on the serial bus. In a master device, a write to this register will initiate transmission/reception of another byte.

Notes: During the last clock cycle the SPIF bit is set, a copy of the received data byte in the shift register is moved to a buffer. When the user reads the serial peripheral data I/O register, the buffer is actually being read.

While the SPIF bit is set, all writes to the SPIDR register are inhibited until the SPICSR register is read.

Warning: A write to the SPIDR register places data directly into the shift register for transmission.

A read to the SPIDR register returns the value located in the buffer and not the content of the shift register (see Figure 36).

managed by exter-

signal con-

pin free for gener-

slave

67/124

Page 68

ST7LITE0, ST7SUPERLITE

SERIAL PERIPHERAL INTERFACE (Cont’d)

Table 16. SPI Register Map and Reset Values

Address

(Hex.)

31 32 33

Label

SPIDR

Reset Value

SPICR

Reset Value

SPICSR

Reset Value

76543210

MSB

xxxxxxx

SPIE

SPIF

SPE

WCOL

SPR20MSTR

OVR

MODF

CPOL

CPHA

SOD

SPR1

SSM

LSB

SPR0

SSI

68/124

Page 69

11.4 8-BIT A/D CONVERTER (ADC)

ST7LITE0, ST7SUPERLITE

11.4.1 Introduction

The on-chip Analog to Digital Converter (ADC) peripheral is a 8-bit, successive approximation converter with internal sample and hold circuitry. This peripheral has up to 5 multiplexed analog input channels (refer to device pin out description) that allow the peripheral to convert the analog voltage levels from up to 5 different sources.

The result of the conversion is stored in a 8-bit Data Register. The A/D converter is controlled through a Control/Status Register.

11.4.2 Main Features

■ 8-bit conversion

■ Up to 5 channels with multiplexed input

■ Linear successive approximation

■ Dual input range

–0 to V

– 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 and low level reference

voltage pins. Conversion accuracy may therefore be impacted

by voltage drops and noise in the event of heavily loaded or badly decoupled power supply lines.

For more details, refer to the Electrical characteristics section.

11.4.3.2 Input Voltage Amplifier

The input voltage can be amplified by a factor of 8 by enabling the AMPSEL bit in the ADAMP register.

When the amplifier is enabled, the input range is 0V to 250 mV.

For example, if V

= 5V, then the ADC can con-

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).

For more details, refer to the Electrical characteristics section.

Note: The amplifier is switched on by the ADON bit in the ADCCSR register, so no additional startup time is required when the amplifier is selected by the AMPSEL bit.

69/124

Page 70

ST7LITE0, ST7SUPERLITE

Figure 43. ADC Block Diagram

AIN0

AIN1

AINx

CPU

DIV 2

ANALOG

MUX

0 1

x 1 or x 8

AMPSEL bit

(ADCAMP Register)

DIV 4

ADC

ADCDR

(ADCAMP Register)

SLOW

bit

CH2 CH10EOC SPEEDADON 0 CH0

HOLD CONTROL

ADC

ADCCSR

ADC

ANALOG TO DIGITAL

CONVERTER

D2 D1D3D7 D6 D5 D4 D0

70/124

Page 71

8-BIT A/D CONVERTER (ADC) (Cont’d)

11.4.3.3 Digital A/D Conversion Result

The conversion is monotonic, meaning that the result never decreases if the analog input does not and never increases if the analog input does not.

If the input voltage (V to V

(high-level voltage reference) then the

DDA

) is greater than or equal

AIN

conversion result in the DR register is FFh (full scale) without overflow indication.

If input voltage (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

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 be

AIN

ADC

SAMPLE

]

sample

capacitor.

■ A/D conversion [duration: t

HOLD

] During this phase, the A/D conversion is computed (8 successive approximations cycles) and the C

sample capacitor is disconnected

ADC

from the analog input pin to get the optimum analog to digital conversion accuracy.

■ The total conversion time:

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 previous measurement load. The advantage of this behaviour is that it minimizes the current consumption on the analog pin in case of single input channel measurement.

11.4.3.5 Software Procedure

Refer to the control/status register (CSR) and data register (DR) in Section 11.4.6 for the bit definitions and to Figure 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 these pins as analog inputs does not affect the ability of the port to be read as a logic input.

In the CSR register:

– Select the CH[2:0] bits to assign the analog

channel to be converted.

ADC Conversion

In the CSR register:

– Set the ADON bit to enable the A/D converter

and to start the first conversion. From this time on, the ADC performs a continuous conversion of the selected channel.

When a conversion is complete

– The EOC bit is set by hardware. – No interrupt is generated. – The result is in the DR register and remains

valid until the next conversion has ended.

A write to the ADCCSR register (with ADON set) aborts the current conversion, resets the EOC bit and starts a new conversion.

Figure 44. ADC Conversion Timings

ADON

HOLD CONTROL

11.4.4 Low Power Modes

Mode Description

WAIT No 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.

CONV

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.

ADCCSR WRITE

OPERATION

EOC BIT SET

11.4.5 Interrupts

None

71/124

Page 72

ST7LITE0, ST7SUPERLITE

8-BIT A/D CONVERTER (ADC) (Cont’d)

11.4.6 Register Description

CONTROL/STATUS REGISTER (ADCCSR)

Read/Write Reset Value: 0000 0000 (00h)

EOC SPEED ADON 0 0 CH2 CH1 CH0

DATA REGISTER (ADCDR)

Read Only Reset Value: 0000 0000 (00h)

D7 D6 D5 D4 D3 D2 D1 D0

Bit 7 = EOC Conversion Complete This bit is set by hardware. It is cleared by software reading the result in the DR register or writing to the CSR register. 0: Conversion is not complete 1: Conversion can be read from the DR register

Bit 6 = SPEED ADC clock selection This bit is set and cleared by software. It is used together with the SLOW bit to configure the ADC clock speed. Refer to the table in the SLOW bit de-

Bits 7:0 = D[7:0] Analog Converted Value This register contains the converted analog value in the range 00h to FFh.

Note: Reading this register reset the EOC flag.

AMPLIFIER CONTROL REGISTER (ADCAMP)

Read/Write Reset Value: 0000 0000 (00h)

scription.

Bit 5 = ADON A/D Converter and Amplifier On This bit is set and cleared by software.

0000SLOW

0: A/D converter and amplifier are switched off 1: A/D converter and amplifier are switched on

Note: Amplifier not available on ST7LITES5 devices

Bit 7:4 = Reserved. Forced by hardware to 0. Bit 3 = SLOW Slow mode

This bit is set and cleared by software. It is used together with the SPEED bit to configure the ADC

Bit 4:3 = Reserved. must always be cleared. Bits 2:0 = CH[2:0] Channel Selection

These bits are set and cleared by software. They select the analog input to convert.

Channel Pin

AIN0 0 0 0 AIN1 0 0 1 AIN2 0 1 0 AIN3 0 1 1 AIN4 1 0 0

CH2 CH1 CH0

Notes:

1. The number of pins AND the channel selection

clock speed as shown on the table below.

ADC

/2 00

CPU

/4 1x

CPU

Bit 2 = AMPSEL Amplifier Selection Bit This bit is set and cleared by software. For ST7LITES5 devices, this bit must be kept at its reset value (0). 0: Amplifier is not selected 1: Amplifier is selected

Note: When AMPSEL=1 it is mandatory that f be less than or equal to 2 MHz.

varies according to the device. Refer to the device pinout.

2. A write to the ADCCSR register (with ADON set) aborts the current conversion, resets the EOC bit and starts a new conversion.

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

SLOW SPEED

ADC

72/124

Page 73

Table 17. ADC Register Map and Reset Values

ST7LITE0, ST7SUPERLITE

Address

(Hex.)

34h 35h

36h

Label

ADCCSR

Reset Value

ADCDR

Reset Value

ADCAMP

Reset Value

76543210

EOC

0 0000

SPEED0ADON

000

CH2

SLOW0AMPSEL

0 0

CH1

0 00

CH0

73/124

Page 74

ST7LITE0, ST7SUPERLITE

12 INSTRUCTION SET

12.1 ST7 ADDRESSING MODES

The ST7 Core features 17 different addressing modes which can be classified in 7 main groups:

Addressing Mode Example

Inherent nop Immediate ld A,#$55 Direct ld A,$55 Indexed ld A,($55,X) Indirect ld A,([$55],X) Relative jrne loop Bit operation bset byte,#5

so, most of the addressing modes may be subdivided in two sub-modes called long and short:

– Long addressing mode is more powerful be-

cause it can use the full 64 Kbyte address space, however it uses more bytes and more CPU cycles.

– Short addressing mode is less powerful because

it can generally only access page zero (0000h 00FFh range), but the instruction size is more compact, and faster. All memory to memory instructions use short addressing modes only (CLR, CPL, NEG, BSET, BRES, BTJT, BTJF, INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP)

The ST7 Assembler optimizes the use of long and short addressing modes.

The ST7 Instruction set is designed to minimize the number of bytes required per instruction: To do

Table 18. ST7 Addressing Mode Overview

Mode Syntax

Inherent nop + 0 Immediate ld A,#$55 + 1 Short Direct ld A,$10 00..FF + 1 Long Direct ld A,$1000 0000..FFFF + 2

No Offset Direct Indexed ld A,(X) 00..FF Short Direct Indexed ld A,($10,X) 00..1FE + 1

Long Direct Indexed ld A,($1000,X) 0000..FFFF + 2 Short Indirect ld A,[$10] 00..FF 00..FF byte + 2 Long Indirect ld A,[$10.w] 0000..FFFF 00..FF word + 2 Short Indirect Indexed ld A,([$10],X) 00..1FE 00..FF byte + 2 Long Indirect Indexed ld A,([$10.w],X) 0000..FFFF 00..FF word + 2 Relative Direct jrne loop PC-128/PC+127 Relative Indirect jrne [$10] PC-128/PC+127 Bit Direct bset $10,#7 00..FF + 1 Bit Indirect bset [$10],#7 00..FF 00..FF byte + 2 Bit Direct Relative btjt $10,#7,skip 00..FF + 2 Bit Indirect Relative btjt [$10],#7,skip 00..FF 00..FF byte + 3

Destination/

Source

Pointer

Address

(Hex.)

00..FF byte + 2

Pointer

Size

(Hex.)

Length (Bytes)

+ 0 (with X register) + 1 (with Y register)

+ 1

Note 1. At the time the instruction is executed, the Program Counter (PC) points to the instruction following JRxx.

74/124

Page 75

ST7 ADDRESSING MODES (Cont’d)

12.1.1 Inherent

All Inherent instructions consist of a single byte. The opcode fully specifies all the required information for the CPU to process the operation.

Inherent Instruction Function

NOP No operation TRAP S/W Interrupt

WFI HALT

RET Sub-routine Return IRET Interrupt Sub-routine Return SIM Set Interrupt Mask RIM Reset Interrupt Mask SCF Set Carry Flag RCF Reset Carry Flag RSP Reset Stack Pointer LD Load CLR Clear PUSH/POP Push/Pop to/from the stack INC/DEC Increment/Decrement TNZ Test Negative or Zero CPL, NEG 1 or 2 Complement MUL Byte Multiplication SLL, SRL, SRA, RLC,

RRC SWAP Swap Nibbles

Wait For Interrupt (Low Power Mode)

Halt Oscillator (Lowest Power Mode)

Shift and Rotate Operations

12.1.2 Immediate

Immediate instructions have two bytes, the first byte contains the opcode, the second byte contains the operand value.

Immediate Instruction Function

LD Load CP Compare BCP Bit Compare AND, OR, XOR Logical Operations ADC, ADD, SUB, SBC Arithmetic Operations

ST7LITE0, ST7SUPERLITE

12.1.3 Direct

In Direct instructions, the operands are referenced by their memory address.

The direct addressing mode consists of two submodes:

Direct (short)

The address is a byte, thus requires only one byte after the opcode, but only allows 00 - FF addressing space.

Direct (long)

The address is a word, thus allowing 64 Kbyte addressing space, but requires 2 bytes after the opcode.

12.1.4 Indexed (No Offset, Short, Long)

In this mode, the operand is referenced by its memory address, which is defined by the unsigned addition of an index register (X or Y) with an offset.

The indirect addressing mode consists of three 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 bytes after the opcode.

12.1.5 Indirect (Short, Long)

The required data byte to do the operation is found by its memory address, located in memory (pointer).

The pointer address follows the opcode. The indirect addressing mode consists of two 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 (long)

The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode.

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ST7LITE0, ST7SUPERLITE

ST7 ADDRESSING MODES (Cont’d)

12.1.6 Indirect Indexed (Short, Long)

This is a combination of indirect and short indexed addressing modes. The operand is referenced by its memory address, which is defined by the unsigned addition of an index register value (X or Y) with a pointer value located in memory. The pointer address follows the opcode.

The indirect indexed addressing mode consists of two 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 Indexed (Long)

The pointer address is a byte, the pointer size is a word, thus allowing 64 Kbyte addressing space, and requires 1 byte after the opcode.

Table 19. Instruct te5uppxessingt

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Page 77

12.2 INSTRUCTION GROUPS

ST7LITE0, ST7SUPERLITE

The ST7 family devices use an Instruction Set consisting of 63 instructions. The instructions may

Load and Transfer LD CLR Stack operation PUSH POP RSP Increment/Decrement INC DEC Compare and Tests CP TNZ BCP Logical operations AND OR XOR CPL NEG Bit Operation BSET BRES Conditional Bit Test and Branch BTJT BTJF Arithmetic operations ADC ADD SUB SBC MUL Shift and Rotates SLL SRL SRA RLC RRC SWAP SLA Unconditional Jump or Call JRA JRT JRF JP CALL CALLR NOP RET Conditional Branch JRxx Interruption management TRAP WFI HALT IRET Condition Code Flag modification SIM RIM SCF RCF

Using a pre-byte

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 are defined. These prebytes modify the meaning of the instruction they precede.

The whole instruction becomes:

PC-2 End of previous instruction PC-1 Prebyte PC Opcode

be subdivided into 13 main groups as illustrated in the following table:

PDY 90 Replace an X based instruction using

immediate, direct, indexed, or inherent addressing mode by a Y one.

PIX 92 Replace an instruction using direct, di-

rect bit, or direct relative addressing mode to an instruction using the corresponding indirect addressing mode. It also changes an instruction using X indexed addressing mode to an instruction using indirect X indexed addressing mode.

PIY 91 Replace an instruction using X indirect

indexed addressing mode by a Y one.

PC+1 Additional word (0 to 2) according to the

number of bytes required to compute the effective address

12.2.1 Illegal Opcode Reset

In order to provide enhanced robustness to the device against unexpected behaviour, a system of il-

These prebytes enable instruction in Y as well as indirect addressing modes to be implemented. They precede the opcode of the instruction in X or the instruction using direct addressing mode. The prebytes are:

legal opcode detection is implemented. If a code to be executed does not correspond to any opcode or prebyte value, a reset is generated. This, combined with the Watchdog, allows the detection and recovery from an unexpected fault or interference.

Note: A valid prebyte associated with a valid opcode forming an unauthorized combination does not generate a reset.

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ST7LITE0, ST7SUPERLITE

INSTRUCTION GROUPS (Cont’d)

Mnemo Description Function/Example Dst Src H I N Z C

ADC Add with Carry A = A + M + C A M H N Z C ADD Addition A = A + M A M H N Z C AND Logical And A = A . M A M N Z BCP Bit compare A, Memory tst (A . M) A M N Z BRES Bit Reset bres Byte, #3 M BSET Bit Set bset Byte, #3 M BTJF Jump if bit is false (0) btjf Byte, #3, Jmp1 M C BTJT Jump if bit is true (1) btjt Byte, #3, Jmp1 M C CALL Call subroutine CALLR Call subroutine relative CLR Clear reg, M 0 1 CP Arithmetic Compare tst(Reg - M) reg M N Z C CPL One Complement A = FFH-A reg, M N Z 1 DEC Decrement dec Y reg, M N Z HALT Halt 0 IRET Interrupt routine return Pop CC, A, X, PC H I N Z C INC Increment inc X reg, M N Z JP Absolute Jump jp [TBL.w] JRA Jump relative always JRT Jump relative JRF Never jump jrf * JRIH Jump if ext. interrupt = 1 JRIL Jump if ext. interrupt = 0 JRH Jump if H = 1 H = 1 ? JRNH Jump if H = 0 H = 0 ? JRM Jump if I = 1 I = 1 ? JRNM Jump if I = 0 I = 0 ? JRMI Jump if N = 1 (minus) N = 1 ? JRPL Jump if N = 0 (plus) N = 0 ? JREQ Jump if Z = 1 (equal) Z = 1 ? JRNE Jump if Z = 0 (not equal) Z = 0 ? JRC Jump if C = 1 C = 1 ? JRNC Jump if C = 0 C = 0 ? JRULT Jump if C = 1 Unsigned < JRUGE Jump if C = 0 Jmp if unsigned >= JRUGT Jump if (C + Z = 0) Unsigned >

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ST7LITE0, ST7SUPERLITE

INSTRUCTION GROUPS (Cont’d)

Mnemo Description Function/Example Dst Src H I N Z C

JRULE Jump if (C + Z = 1) Unsigned <= LD Load dst <= src reg, M M, reg N Z MUL Multiply X,A = X * A A, X, Y X, Y, A 0 0 NEG Negate (2's compl) neg $10 reg, M N Z C NOP No Operation OR OR operation A = A + M A M N Z POP Pop from the Stack pop reg reg M

pop CC CC M H I N Z C PUSH Push onto the Stack push Y M reg, CC RCF Reset carry flag C = 0 0 RET Subroutine Return RIM Enable Interrupts I = 0 0 RLC Rotate left true C C <= Dst <= C reg, M N Z C RRC Rotate right true C C => Dst => C reg, M N Z C RSP Reset Stack Pointer S = Max allowed SBC Subtract with Carry A = A - M - C A M N Z C SCF Set carry flag C = 1 1 SIM Disable Interrupts I = 1 1 SLA Shift left Arithmetic C <= Dst <= 0 reg, M N Z C SLL Shift left Logic C <= Dst <= 0 reg, M N Z C SRL Shift right Logic 0 => Dst => C reg, M 0 Z C SRA Shift right Arithmetic Dst7 => Dst => C reg, M N Z C SUB Subtraction A = A - M A M N Z C SWAP SWAP nibbles Dst[7..4] <=> Dst[3..0] reg, M N Z TNZ Test for Neg & Zero tnz lbl1 N Z TRAP S/W trap S/W interrupt 1 WFI Wait for Interrupt 0 XOR Exclusive OR A = A XOR M A M N Z

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ST7LITE0, ST7SUPERLITE

13 ELECTRICAL CHARACTERISTICS

13.1 PARAMETER CONDITIONS

Unless otherwise specified, all voltages are referred to V

13.1.1 Minimum and Maximum values

Unless otherwise specified the minimum and maximum values are guaranteed in the worst conditions of ambient temperature, supply voltage and frequencies by tests in production on 100% of the devices with an ambient temperature at T and T

A=TA

range). Data based on characterization results, design

simulation and/or technology characteristics are indicated in the table footnotes and are not tested in production. Based on characterization, the min-

=25°C

max (given by the selected temperature

80/124

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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 functional operation of the device under these condi-

13.2.1 Voltage Characteristics

13.2.2 Current Characteristics

tions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.

13.2.3 Thermal Characteristics

Notes:

1. Directly connecting the I/O pins to V tion occurs (for example, due to a corrupted program counter). To guarantee safe operation, this connection has to be done through a pull-up or pull-down resistor (typical: 10kΩ for I/Os). Unused I/O pins must be tied in the same way to V or VSS according to their reset configuration.

2. I respected, the injection current must be limited externally to the I while a negative injection is induced by VIN<VSS.

3. All power (V

4. Negative injection disturbs the analog performance of the device. In particular, it induces leakage currents throughout the device including the analog inputs. To avoid undesirable effects on the analog functions, care muss 14e6 194.76n:ut

must never be exceeded. This is implicitly insured if VIN maximum is respected. If VIN maximum cannot be

INJ(PIN)

) and ground (VSS) lines must always be connected to the external supply.

or V

could damage the device if an unexpected change of the I/O configura-

value. A positive injection is induced by VIN>V

INJ(PIN)

inp/O pire mushativaTo

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Page 83

ST7LITE0, ST7SUPERLITE

13.3.2 Operating Conditions with Low Voltage Detector (LVD)

= -40 to 85°C, unless otherwise specified

Symbol Parameter Conditions Min Typ Max Unit

IT+

IT-

(LVD)

hys

POR

g(VDD)

DD(LVD

Reset release threshold

(LVD)

rise)

Reset generation threshold

fall)

LVD voltage threshold hysteresis V VDD rise time rate Filtered glitch delay on V

2) DD

) LVD/AVD current consumption 220 µA

High Threshold Med. Threshold Low Threshold

(LVD)

-V

IT-

(LVD)

IT+

Not detected by the LVD 150 ns

Notes:

1. Not tested in production.

2. Not tested in production. The V When the V

slope is outside these values, the LVD may not ensure a proper reset of the MCU.

rise time rate condition is needed to ensure a correct device power-on and LVD reset.

13.3.3 Auxiliary Voltage Detector (AVD) Thresholds

= -40 to 85°C, unless otherwise specified

Symbol Parameter Conditions Min Typ Max Unit

High Threshold Med. Threshold Low Threshold

IT+

-V

(AVD)

IT-

(AVD)

fall 0.45 V

V V

∆V

IT+

IThys

(AVD)

IT-

1=>0 AVDF flag toggle threshold

rise)

0=>1 AVDF flag toggle threshold

fall)

AVD voltage threshold hysteresis V Voltage drop between AVD flag set

and LVD reset activation

4.00

3.40 1)

2.65

3.80

3.20

2.40

4.25

3.60

2.90

4.05

3.40

2.70

4.50

3.80

3.15

4.30

3.65

2.90

200 mV

20 20000 µs/V

4.40

3.90

3.20

4.30

3.70

2.90

4.70

4.10

3.40

4.60

3.90

3.20

5.00

4.30

3.60

4.90

4.10

3.40

150 mV

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).

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ST7LITE0, ST7SUPERLITE

OPERATING CONDITIONS (Cont’d)

The RC oscillator and PLL characteristics are temperature-dependent and are grouped in four tables.

13.3.4.1 Devices with “6” order code suffix (tested for T

Symbol Parameter Conditions Min Typ Max Unit

ACC I

DD(RC)

su(RC)

PLL

Internal RC oscillator frequency

Accuracy of Internal RC oscillator with

RCCR=RCCR0

RC oscillator current consumption

RC oscillator setup time TA=25°C,VDD=5V 10 x8 PLL input clock 1

RCCR = FF (reset value), T RCCR = RCCR0

2 )

,TA=25°C,VDD=5V 1000 TA=25°C,VDD=4.5 to 5.5V -1 +1% T

=-40 to +85°C,VDD=5V -5 +2 %

=0 to +85°C,VDD=4.5 to 5.5V -2

=25°C,VDD=5V 970

= -40 to +85°C) @ VDD = 4.5 to 5.5V

=25°C,VDD=5V 760

kHz

µA

µs

MHtL

Notes:

1. Data based on characterization results, not tested in production

2. RCCR0 is a factory-calibrated setting for 1000kHz with ±0.2 accuracy @ T CILLATOR ADJUSTMENT” on page 24

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 25.

STAB

=25°C, VDD=5V. See “INTERNAL RC OS-

is required to reach ACC

accuracy.

PLL

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Page 85

ST7LITE0, ST7SUPERLITE

OPERATING CONDITIONS (Cont’d)

13.3.4.2 Devices with ‘”6” order code suffix (tested for T

Symbol Parameter Conditions Min Typ Max Unit

ACC I

DD(RC)

su(RC)

Internal RC oscillator frequency

Accuracy of Internal RC oscillator when calibrated

with RCCR=RCCR1 RC oscillator current con-

sumption

RCCR = FF (reset value), T RCCR=RCCR1

,TA=25°C,VDD= 3V 700 TA=25°C,VDD=3V -2 +2 % T

=25°C,VDD=2.7 to 3.3V -25 +25 %

1)2)

=-40 to +85°C,VDD=3V -15 15 %

=25°C,VDD=3V 700

= -40 to +85°C) @ VDD = 2.7 to 3.3V

=25°C, VDD= 3.0V 560

kHz

µA

Notes:

1. Data based on characterization results, not tested in production

2. RCCR1 is a factory-calibrated setting for 700kHz with ±2% accuracy @ T CILLATOR ADJUSTMENT” on page 24.

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 25.

STAB

=25°C, VDD=3V. See “INTERNAL RC OS-

is required to reach ACC

accuracy

PLL

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Page 87

OPERATING CONDITIONS (Cont’d)

ST7LITE0, ST7SUPERLITE

Figure 52. PLL ∆f

∆f

Max

Min

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 External Input Clock Frequency (MHz)

3.3 3

2.7

w(JIT)

Figure 54. PLLx8 Output vs CLKIN frequency

11.00

9.00

7.00

5.00

3.00

Output Frequency (MHz)

1.00

0.85 0.9 1 1.5 2 2.5 External Input Clock Frequency (MHz)

5.5 5

4.5 4

Note: f

OSC

= f

CLKIN

/2*PLL4

Note: f

OSC

= f

CLKIN

/2*PLL8

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ST7LITE0, ST7SUPERLITE

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 mode for which the clock is stopped).

source current consumption. To get the total de-

13.4.1 Supply Current

= -40 to +85°C unless otherwise specified

Symbol Parameter Conditions Typ Max Unit

Supply current in RUN mode Supply current in WAIT mode f Supply current in SLOW mode f

Supply current in SLOW WAIT mode f Supply current in HALT mode

=8MHz

CPU

=8MHz

CPU

=250kHz

CPU

=5.5V V

=250kHz

CPU

-40°C≤TA≤+85°C T

= +85°C 5

Notes:

1. CPU running with memory access, all I/O pins in input mode with a static value at V in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.

2. All I/O pins in input mode with a static value at V driven by external square wave, LVD disabled.

3. SLOW mode selected with f (no load), all peripherals in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.

4. SLOW-WAIT mode selected with f

or VSS (no load), all peripherals in reset state; clock input (CLKIN) driven by external square wave, LVD disabled.

based on f

CPU

based on f

CPU

5. All I/O pins in output mode with a static value at V

tested in production at V

max and f

CPU

max.

or VSS (no load), all peripherals in reset state; clock input (CLKIN)

divided by 32. All I/O pins in input mode with a static value at VDD or

OSC

divided by 32. All I/O pins in input mode with a static value at

OSC

(no load), LVD disabled. Data based on characterization results,

4.50 7.00

1.75 2.70

0.75 1.13

0.65 1

0.50 10 100

µA

or VSS (no load), all peripherals

Figure 55. Typical IDD in RUN vs. f

5.0

4.0

3.0

2.0

Idd (mA)

1.0

0.0

8MHz 4MHz 1MHz

2.4 2.7 3. 7 4.5 5 5.5

Vdd (V)

CPU

Figure 56. Typical IDD in SLOW vs. f

0.80

0.70

0.60

0.50

0.40

0.30

Idd (mA)

0.20

0.10

0.00

250kHz 125kHz

62.5k Hz

2.4 2.7 3.7 4.5 5 5.5

Vdd (V)

CPU

88/124

Page 89

ST7LITE0, ST7SUPERLITE

Figure 57. Typical IDD in WAIT vs. f

2.0

1.5

1.0

Idd (mA)

0.5

0.0

8MHz 4MHz 1MHz

2.4 2.7 3.7 4.5 5 5.5

Vdd (V)

CPU

Figure 58. Typical IDD in SLOW-WAIT vs. f

0.70

0.60

0.50

0.40

0.30

Idd (mA)

0.20

0.10

0.00

250kHz 125kHz

62.5kHz

2.4 2.7 3.7 4.5 5 5.5

Vdd (V)

CPU

89/124

Page 90

ST7LITE0, ST7SUPERLITE

SUPPLY CURRENT CHARACTERISTICS (Cont’d)

Figure 59. Typical I at V

5.00

4.50

4.00

3.50

3.00

2.50

2.00

Idd (mA)

1.50

1.00

0.50

0.00

= 5V and f

-45 25 90 130

vs. Temperature

= 8MHz

CPU

Temperature (°C)

RUN WAIT SLOW SLOW WAIT

13.4.2 On-chip peripherals

Symbol Parameter Conditions Typ Unit

=4MHz VDD=3.0V 150

DD(AT)

DD(SPI)

DD(ADC)

12-bit Auto-Reload Timer supply current SPI supply current ADC supply current when converting

CPU

=8MHz VDD=5.0V 250

CPU

=4MHz VDD=3.0V 50

CPU

=8MHz VDD=5.0V 300

CPU

=3.0V 780

ADC

=4MHz

=5.0V 1100

µA

1. Data based on a differential IDD measurement between reset configuration (timer stopped) and a timer running in PWM mode at f

2. Data based on a differential I tion (data sent equal to 55h).

3. Data based on a differential I plifier off.

=8MHz.

cpu

measurement between reset configuration and a permanent SPI master communica-

measurement between reset configuration and continuous A/D conversions with am-

90/124

Page 91

13.5 CLOCK AND TIMING CHARACTERISTICS

ST7LITE0, ST7SUPERLITE

Subject to general operating conditions for V

, f

OSC

, and TA.

13.5.1 General Timings

Symbol Parameter

c(INST)

v(IT)

Instruction cycle time f Interrupt reaction time

v(IT)

= ∆t

c(INST)

+ 10

Conditions Min Typ

=8MHz

CPU

=8MHz

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)

Max Unit

2312t

CPU

250 375 1500 ns

10 22 t

CPU

1.25 2.75 µs

cycles needed to fin-

CPU

91/124

Page 92

ST7LITE0, ST7SUPERLITE

13.6 MEMORY CHARACTERISTICS

= -40°C to 85°C, unless otherwise specified

13.6.1 RAM and Hardware Registers

Symbol Parameter Conditions Min Typ Max Unit

Data retention mode

13.6.2 FLASH Program Memory

Symbol Parameter Conditions Min Typ Max Unit

V t t

prog RET

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

HALT mode (or RESET) 1.6 V

2.4 5.5

TA=−40 to +85°C 5 10 T

=+25°C 0.24 0.48

TA=+55°C TA=+25°C 10K

20 years

Read / Write / Erase

modes

= 8MHz, VDD = 5.5V

CPU

2.6

No Read/No Write Mode 100 µA

Power down mode / HALT 0 0.1 µA

cycles

Symbol Parameter Conditions Min Typ Max Unit

V t

prog

ret RW

Operating voltage for EEPROM write/erase

Programming time for 1~32 bytes Data retention Write erase cycles

=−40 to +85°C 5 10

TA=+55°C

TA=+25°C 300K

2.4 5.5

20 years

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-

2. Up to 32 bytes can be programmed at a time.

3. The data retention time increases when the T

decreases.

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.

cycles

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Page 93

ST7LITE0, ST7SUPERLITE

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

and VSS through

a 100pF capacitor, until a functional disturbance occurs. This test conforms with the IEC 1000-44 standard.

A device reset allows normal operations to be resumed. The test results are given in the table below based on the EMS levels and classes defined in application note AN1709.

13.7.1.1 Designing hardened software to avoid noise problems

EMC characterization and optimization are performed at component level with a typical applica-

tion environment and simplified MCU software. It should be noted that good EMC performance is highly dependent on the user application and the software in particular.

Therefore it is recommended that the user applies EMC software optimization and prequalification tests in relation with the EMC level requested for his application.

Software recommendations:

The software flowchart must include the management of runaway conditions such as:

– Corrupted program counter – Unexpected reset – Critical Data corruption (control registers...)

Prequalification trials:

Most of the common failures (unexpected reset and program counter corruption) can be reproduced by manually forcing a low state on the RESET pin or the Oscillator pins for 1 second.

To complete these trials, ESD stress can be applied directly on the device, over the range of specification values. When unexpected behaviour is detected, the software can be hardened to prevent unrecoverable errors occurring (see application note AN1015).

Symbol Parameter Conditions

FESD

FFTB

Voltage limits to be applied on any I/O pin to induce a functional disturbance

Fast transient voltage burst limits to be applied through 100pF on V tional disturbance

and V

pins to induce a func-

VDD=5V, TA=+25°C, f conforms to IEC 1000-4-2

=5V, TA=+25°C, f

conforms to IEC 1000-4-4

13.7.2 Electro Magnetic Interference (EMI)

Based on a simple application running on the product (toggling 2 LEDs through the I/O ports), the product is monitored in terms of emission. This emission test is in line with the norm SAE J 1752/ 3 which specifies the board and the loading of each pin.

Symbol Parameter Conditions

=5V, TA=+25°C,

EMI

Notes:

1. Data based on characterization results, not tested in production.

Peak level

SO16 package, conforming to SAE J 1752/3

Monitored

Frequency Band

0.1MHz to 30MHz 8 14 130MHz to 1GHz 26 28

SAE EMI Level 3.5 4 -

=8MHz

OSC

=8MHz

OSC

Max vs. [f

1/4MHz 1/8MHz

OSC/fCPU

]

Level/ Class

2B 3B

Unit

dBµV30MHz to 130MHz 27 32

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ST7LITE0, ST7SUPERLITE

EMC CHARACTERISTICS (Cont’d)

13.7.3 Absolute Maximum Ratings (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 application note AN1181.

Absolute Maximum Ratings

Symbol Ratings Conditions Maximum value

ESD(HBM)

Notes:

1. Data based on characterization results, not tested in production.

Electro-static discharge voltage (Human Body Model)

13.7.3.2 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) and a current injection (applied to each input, output and configurable I/O pin) are performed on each sample. This test conforms to the EIA/JESD 78 IC latch-up standard. For more details, refer to the application note AN1181.

13.7.3.1 Electro-Static Discharge (ESD)

Electro-Static Discharges (a positive then a negative pulse separated by 1 second) are applied to the pins of each sample according to each pin combination. The sample size depends on the number of supply pins in the device (3 parts*(n+1) supply pin). This test conforms to the JESD22A114A/A115A standard.

=+25°C

■ DLU: Electro-Static Discharges (one positive

4000 V

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. For more details, refer to the application note AN1181.

Unit

Electrical Sensitivities

Symbol Parameter Conditions Class

LU Static latch-up class TA=+25°C A

DLU Dynamic latch-up class

Notes:

1. Class description: A Class is an STMicroelectronics internal specification. All its limits are higher than the JEDEC specifications, that means when a device belongs to Class A it exceeds the JEDEC standard. B Class strictly covers all the JEDEC criteria (international standard).

=5.5V, f

=4MHz, TA=+25°C

OSC

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Page 95

ST7LITE0, ST7SUPERLITE

13.8 I/O PORT PIN CHARACTERISTICS

13.8.1 General Characteristics

Subject to general operating conditions for V

Symbol Parameter Conditions Min Typ Max Unit

V V

f(IO)out

r(IO)out

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 61).

4. To generate an external interrupt, a minimum pulse width has to be applied on an I/O port pin configured as an external interrupt source.

Input low level voltage V

Input high level voltage 0.7xV

Schmitt trigger voltage

hys

hysteresis

Input leakage current V

Static current consumption 2)Floating input mode 200

Weak pull-up equivalent

resistor I/O pin capacitance 5 pF

Output high to low level fall time

Output low to high level rise time

External interrupt pulse time

pull-up equivalent resistor is based on a resistive transistor (corresponding I

1) SS≤VIN≤VDD

IN=VSS

CL=50pF Between 10% and 90%

, f

, and TA unless otherwise specified.

OSC

- 0.3 0.3xV

400 mV

VDD=5V 50 120 250 V

=3V 160

25 25

current characteristics de-

+ 0.3

±1

µA kΩ

CPU

Figure 60. Two typical Applications with unused I/O Pin

10kΩ

Caution: During normal operation the ICCCLK pin must be pulled- up, internally or externally

(external pull-up of 10k mandatory in This is to avoid entering ICC mode unexpectedly during a reset. noisy environment).

Figure 61. Typical I

TO BE CHARACTERIZED

Ipu(uA)

2 2.5 3 3.5 4 4.5 5 5.5 6

vs. VDD with VIN=V

Ta=140°C Ta=95°C Ta=25°C Ta=-45°C

Vdd(V)

ST7XXX

10kΩ

UNUSED I/O PORT

ST7XXX

95/124

Page 96

ST7LITE0, ST7SUPERLITE

I/O PORT PIN CHARACTERISTICS (Cont’d)

13.8.2 Output Driving Current

, f

Subject to general operating conditions for V

Symbol Parameter Conditions Min Max Unit

Output low level voltage for a standard I/O pin when 8 pins are sunk at same time (see Figure 65)

Output low level voltage for a high sink I/O pin when 4 pins are sunk at same time (see Figure 67)

when 4 pins are sourced at same time (see Figure 73)

Output high level voltage for an I/O pin

Output low level voltage for a standard I/O pin when 8 pins are sunk at same time

1)3)

(see Figure 64) Output low level voltage for a high sink I/O pin

when 4 pins are sunk at same time

when 4 pins are sourced at same time

Output high level voltage for an I/O pin

2)3)

Output low level voltage for a standard I/O pin when 8 pins are sunk at same time

1)3)

(see Figure 63) 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)

when 4 pins are sourced at same time (see Figure 70)

, and TA unless otherwise specified.

CPU

IIO=+5mA TA≤85°C

≥85°C

=+2mA TA≤85°C

=+20mA,TA≤85°C

=5V

=+8mA TA≤85°C

=-5mA, TA≤85°C

=-2mA TA≤85°C

T T T T T

≥85°C

IIO=+2mA TA≤85°C

≥85°C

=+8mA TA≤85°C

=3.3V

=-2mA TA≤85°C

T T

≥85°C

IIO=+2mA TA≤85°C

≥85°C

=+8mA TA≤85°C

=-2mA TA≤85°C

=2.7V

T T

≥85°C

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

Notes:

1. The I (I/O ports and control pins) must not exceed I

2. The I I

current sunk must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of I

current sourced must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of

(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 62. Typical VOL at VDD=2.4V (standard) Figure 63. 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

96/124

TO BE CHARACTERIZED

0.01 1 2 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

0.01 1 2 lio (mA)

-45°C 0°C 25°C 90°C 130°C

Page 97

I/O PORT PIN CHARACTERISTICS (Cont’d)

ST7LITE0, ST7SUPERLITE

Figure 64. Typical V

0.70

0.60

0.50

0.40

0.30

VOL at VDD=3.3V

0.20

0.10

0.00

0.01 1 2 3

Figure 66. 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 65. Typical VOL at VDD=5V (standard)

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 68. 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)

lio (mA)

lio (m A)

at VDD=2.4V (high-sink)

lio (m A)

-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 67. Typical V

2.50

2.00

1.50

1.00

0.50

Vol (V) at VDD=5V (HS)

0.00 6 7 8 9 10 15 20 25 30 35 40

at VDD=5V (high-sink)

lio (mA)

-45 0°C 25°C 90°C 130°C

97/124

Page 98

ST7LITE0, ST7SUPERLITE

I/O PORT PIN CHARACTERISTICS (Cont’d)

Figure 69. 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 70. Typical V

1.20

1.00

0.80

0.60

DD-VOH

lio (mA)

DD-VOH

at VDD=2.4V

at VDD=2.7V

-45°C 0°C 25°C 90°C 130°C

Figure 71. Typical V

Figure 72. Typical V

DD-VOH

at VDD=3V

at VDD=4V

0.40

0.20

0.00

-0.01 -1 -2

Figure 73. Typical V

DD-VOH

at VDD=5V

98/124

Page 99

I/O PORT PIN CHARACTERISTICS (Cont’d)

ST7LITE0, ST7SUPERLITE

Figure 74. Typical V

0.70

0.60

0.50

0.40

0.30

0.20

Vol (V) at lio=2mA

0.10

0.00

2.4 2.7 3.3 5

Figure 75. 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

2.4 3 5

vs. VDD (standard I/Os)

VDD (V)

vs. VDD (high-sink I/Os)

VDD (V)

-45 0°C 25°C 90°C 130°C

0.06

0.05

0.04

0.03

0.02

Vol (V) at lio=0.01mA

0.01

0.00

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

2.4 2.7 3.3 5

VDD (V)

2.4 3 5

VDD (V )

-45 0°C 25°C 90°C 130°C

Figure 76. Typical V

1.80

1.70

1.60

1.50

1.40

1.30

1.20

1.10

VDD-VOH at lio=-5mA

1.00

0.90

0.80 45

DD-VOH

VDD

vs. V

-45°C 0°C 25°C 90°C 130°C

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

99/124

Page 100

ST7LITE0, ST7SUPERLITE

13.9 CONTROL PIN CHARACTERISTICS

13.9.1 Asynchronous RESET

= -40°C to 85°C, unless otherwise specified

Symbol Parameter Conditions Min Typ Max Unit

V V

w(RSTL)out

h(RSTL)in

g(RSTL)in

Input low level voltage V

Input high level voltage 0.7xV

Schmitt trigger voltage hysteresis

hys

IIO=+5mA TA≤85°C

Output low level voltage

Pull-up equivalent resistor

3) 1)

VDD=5V

=+2mA TA≤85°C

VDD=5V 20 40 80 V

=3V 30

≥85°C ≥85°C

- 0.3 0.3xV

0.5

0.2

Generated reset pulse duration Internal reset sources 30 µs External reset pulse hold time

20 µs

Filtered glitch duration 200 ns

+ 0.3

1.0

1.2

0.4

0.5 kΩ

Notes:

1. Data based on characterization results, not tested in production.

2. The I sum of I

3. The R V

ILmax

current sunk must always respect the absolute maximum rating specified in section 13.2.2 on page 81 and the

(I/O ports and control pins) must not exceed I

pull-up equivalent resistor is based on a resistive transistor. Specified for voltages on RESET pin between

and V

VSS

4. To guarantee the reset of the device, a minimum pulse has to be applied to the RESET pin. All short pulses applied on pin with a duration below t

RESET

h(RSTL)in

can be ignored.

100/124

Datasheet ST7LITE0, ST7SUPERLITE Datasheet (STMicroelectronics)

Specifications and Main Features

Frequently Asked Questions

User Manual

ST7LITE0, ST7SUPERLITE

1 INTRODUCTION

2 PIN DESCRIPTION

3 REGISTER & MEMORY MAP

4 FLASH PROGRAM MEMORY

4.1 Introduction

4.2 Main Features

4.3 PROGRAMMING MODES

4.3.1 In-Circuit Programming (ICP)

4.3.2 In Application Programming (IAP)

4.4 ICC interface

4.5 Memory Protection

4.5.1 Read out Protection

4.5.2 Flash Write/Erase Protection

4.6 Related Documentation

4.7 Register Description

5 DATA EEPROM

5.1 INTRODUCTION

5.2 MAIN FEATURES

5.3 MEMORY ACCESS

5.4 POWER SAVING MODES

5.5 ACCESS ERROR HANDLING

5.6 Data EEPROM Read-out Protection

5.7 REGISTER DESCRIPTION

6 CENTRAL PROCESSING UNIT

6.1 INTRODUCTION

6.2 MAIN FEATURES

6.3 CPU REGISTERS

7 SUPPLY, RESET AND CLOCK MANAGEMENT

7.1 INTERNAL RC OSCILLATOR ADJUSTMENT

7.2 PHASE LOCKED LOOP

7.3 REGISTER DESCRIPTION

7.4 RESET SEQUENCE MANAGER (RSM)

7.4.1 Introduction

7.4.3 External Power-On RESET

7.4.4 Internal Low Voltage Detector (LVD) RESET

7.4.5 Internal Watchdog RESET

8 INTERRUPTS

8.1 NON MASKABLE SOFTWARE INTERRUPT

8.2 EXTERNAL INTERRUPTS

8.3 PERIPHERAL INTERRUPTS

8.4 SYSTEM INTEGRITY MANAGEMENT (SI)

8.4.1 Low Voltage Detector (LVD)

8.4.2 Auxiliary Voltage Detector (AVD)

8.4.3 Low Power Modes

8.4.3.1 Interrupts

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

9 POWER SAVING MODES

9.1 INTRODUCTION

9.2 SLOW MODE

9.3 WAIT MODE

9.4 ACTIVE-HALT AND HALT MODES

9.4.1 ACTIVE-HALT MODE

9.4.2 HALT MODE

9.4.2.1 HALT Mode Recommendations

10 I/O PORTS

10.1 INTRODUCTION

10.2 FUNCTIONAL DESCRIPTION

10.2.1 Input Modes

10.2.2 Output Modes

10.2.3 Alternate Functions

10.3 UNUSED I/O PINS

10.4 LOW POWER MODES

10.5 INTERRUPTS

10.6 I/O PORT IMPLEMENTATION

11 ON-CHIP PERIPHERALS

11.1 LITE TIMER (LT)

11.1.1 Introduction

11.1.2 Main Features

11.1.3 Functional Description

11.1.3.1 Watchdog

11.1.6 Register Description

11.2 12-BIT AUTORELOAD TIMER (AT)

11.2.1 Introduction

11.2.2 Main Features

11.2.3 Functional Description PWM Mode