SAFE ST7 EVALUATION BOARD - STMicroelectronics...interrupt and resume the one previously being...

SAFE ST7EVALUATION BOARD

(ST7FOPTIONS-EVAL)

USER MANUAL

June 2002

DOC- ST7FOPTIONS-EVAL

1

USE IN LIFE SUPPORT DEVICES OR SYSTEMS MUST BE EXPRESSLY AUTHORIZED.

STMicroelectronics PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF STMicroelectronics. As used herein:

1. Life support devices or systems are thosewhich (a) are intended for surgical implant intothe body, or (b) support or sustain life, andwhose failure to perform, when properly used inaccordance with instructions for use providedwith the product, can be reasonably expectedto result in significant injury to the user.

2. A critical component is any component of a lifesupport device or system whose failure toperform can reasonably be expected to causethe failure of the life support device or system,or to affect its safety or effectiveness.

1

ST72F26x MCU FAMILY

SAFE ST7 EVALUATION BOARD USER MANUAL

1 INTRODUCTION

The objective of the Safe ST7 Evaluation Board is to allow you to try out all the special fea-tures embedded in the ST72F26x MCU family. You can learn how each feature works andhow to use them the best way by playing with the user controls and jumper settings. For ex-ample, you can check out what happens to your application when the voltage becomes erraticor the clock signal suddenly fails.

Examples of what you can do:

■ Save application data in E2PROM when a power cut occurs and/or the main clock sourcefails (using the AVD and CSS options). Prove it works by resuming the application exactlywhere it left off after restoring the data saved by the AVD interrupt routine.

■ Drive LEDs directly (using the MCU’s high sink current I/O ports)

■ Experiment with different clock sources: external crystal or ceramic resonator, internal RCoscillator, external clock signal. The advantages of the internal RC: less cost, lesscomponents, less power consumption!

■ Check out the safe operation of the MCU in varying supply voltage conditions. You changethe voltage using a trimmer. The voltage level is displayed on a 3-digit display. The LVD willautomatically hold the MCU in reset state while the voltage is below the safe threshold. Noneed for an external reset circuit so more savings in board space and components.

■ Select different power sources, on-board 9V battery or external power supply

■ Change E2PROM data or Flash program memory on-the-fly using In-ApplicationProgramming (IAP)

■ Use Nested interrupts to let you interrupt an interrupt routine, service a higher priorityinterrupt and resume the one previously being serviced.

This evaluation board incorporates basic input sources such as push-buttons, analog trimmeror output sources (LEDs, 7-segment displays, buzzer) and a wire-wrap area so you can easilydevelop your own application.

The following development tools can be ordered separately: assembler, linker, C compiler,source level debugger, hardware emulator, programming boards and gang programmer.

For ordering information, see our website at http://mcu.st.com or contact your local salesoffice.

June 2002 1/28

1

Table of Contents

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28

1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 SAFE ST7 EVALUATION BOARD DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 BOARD FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.3 POWER SUPPLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.4 OSCILLATION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.5 ICP (IN-CIRCUIT PROGRAMMING) CONNECTOR . . . . . . . . . . . . . . . . . . . . . . 7

2.6 I²C SERIAL COMMUNICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.7 SPI SERIAL COMMUNICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.8 I/O PORT FUNCTIONALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.8.1 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.8.2 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.8.3 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.9 JUMPER DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.1 W2 - Variable voltage enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.2 W3 - Board reference voltage selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.3 TP4 and TP5 - GND and VDD pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.4 W6 - MCU power consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.5 W4 and W5 - Source clock selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.6 W8 and W9 - External interrupts enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.9.7 W10 - Buzzer enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.8 TP1, TP2 and TP3 - Port connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.9 W15 - LEDs enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.10W13 and W14 - Analog inputs enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.11W12 - High Sink I/O test enable/disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.12W16, W17 and W18 - 7 seg Displays enable/disable . . . . . . . . . . . . . . . . . . . . . . . 112.9.13W1 - ICP Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.14W7 - I²C connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.9.15JP11 - SPI Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3 SOFTWARE DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.1 OPTION BYTE CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.2 MAIN MCU INITIALIZATION ROUTINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.3 COUNTERS AND USE OF TIMING RESOURCES . . . . . . . . . . . . . . . . . . . . . . 13

3.4 INTERRUPT SERVICE ROUTINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Introduction

3.5 MAIN PROGRAM ROUTINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.6 OPERATING THE DEMOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153.6.1 Running the LVD Demo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.6.1.1LVD Demo Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183.6.2 Running the AVD Demo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.6.2.1AVD Demo Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193.6.3 Running the CSS Demo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.6.3.1CSS Demo Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.6.4 Running the High I/O current demo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.6.4.1High Sink Demo Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223.6.5 Running the IAP demo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.6.5.1IAP Demo Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.6.6 Running the Nested & Concurrent Interrupts demo . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.6.6.1Nested & Concurrent Interrupts Demo Description . . . . . . . . . . . . . . . . . . . . 25

4 APPENDIX 1: SAFE ST7 EVALUATION BOARD SCHEMATIC . . . . . . . . . . . . . . . . 26

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Safe ST7 Evaluation Board DESCRIPTION

2 SAFE ST7 EVALUATION BOARD DESCRIPTION

The Safe ST7 Evaluation Board is designed to support any of the SDIP32 package devicesfrom the ST72F264 family (ST72F264, 262, 260).

2.1 OVERVIEW

This board is supplied ready-to-use, to let you try out all the functions described in this manual.The board is delivered with a SDIP32 socket. You will have to build an adapter if you needevaluate the ST72F264 in other packages. Additional hardware functions can be implementedby installing components in the wire-wrap area as shown in Figure 1 below.Figure 1. Safe ST7 Evaluation Board layout

For more details, please refer to the schematic drawing in the appendix.

Battery

Wire-Wrap Area

Two PushButtons

ResetButton

Buzzer

Three7-segmentsLEDs

VoltageTrimmer

ICP Connector

PA, PB & PC Ports

Connector SPI

Connector I²C

Output LEDs

MCU +Clock system

4/28

1


The main Safe ST7 Evaluation Board components are:

- Socketed ST72F264

- 16MHz crystal

- Reset pushbutton

- ICP connector

- Socketed I²C 8K byte EEPROM (M24C08)

- Socketed SPI 4K byte EEPROM (M95040)

- 2 pushbuttons for external interrupts

- 22 pins for expansion ports

- Row of 8 LEDs for displaying binary values

- Three 7-segment LEDs

- High efficiency LED

- Potentiometer for main voltage variation

- Potentiometer for I/O current variation

- 9-volt battery

- Buzzer

- Wire-Wrap area

2.2 BOARD FEATURES

- Low voltage detector (3 levels programmable by option bytes)

- Auxiliary voltage detector

- Multi-Oscillator and Clock Security System

- High Sink/source current

- Nested/ Concurrent Interrupts

- In-Application Programming

- In-Circuit Programming

- I²C & SPI communications interfaces

- 10-bit ADC

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2.3 POWER SUPPLY

This board is supplied with a PP3 9-volt battery demonstrating the board’s low power con-sumption. A complementary DC power supply input (ref. J1) is provided to supply the boardby external ( 9 to 13 Volt) power. When using this power supply, take care to respect the po-larities marked next to the two-pole connector.

Warning: Disconnect the battery from its socket when the Safe ST7 EvaluationBoard is not in use.

The reference voltage on board (VDD) is selected through the W3 jumper. You can choose be-tween two reference voltages, either a regulated 5 volts and or a voltage that varies, bymoving the R5 trimmer position, from 0 to 5.6 Volts as shown in Figure 2.Figure 2. How to Change the Board Voltage Reference

The 1N4004 diodes provide for polarity protection and the LD1 LED provides an indication thatpower is being supplied to the board.

2.4 OSCILLATION SYSTEM

The board is designed to be used with an on-board 16-MHz crystal. This allows you to con-figure the CPU frequency up to 8 MHz.

The oscillator system is designed to fit a range of application needs, and you can choose be-tween three different sources using the W4 and W5 jumpers as shown in Figure 3.

VDD Board

Variable Voltage5 regulated VoltsW3

VDD Board

Variable Voltage5 regulated VoltsW3

5 regulated Volts selected Variable Voltage selected

RV1

6/28


Figure 3. How to Change the Oscillator Frequency Source

2.5 ICP (IN-CIRCUIT PROGRAMMING) CONNECTOR

You can use In Circuit Programming (ICP) to update the entire contents of the Flash memory(including option bytes) using the ICC protocol. Figure 4 shows the connector pin assignment.If you are connecting an ST Programming Tool to Safe ST7 Evaluation Board just connectcable provided with the ST Programming Tool to the ICP connector "W2" and then power onthe board.Figure 4. How to use the ICP Connector

Crystal Resonator Internal RC oscillator External Clock

C4

C5W5

W4

C4

C5W5

W4C4

C5 W5

W4

XT1 XT1 XT1

12

910

Cable to ST Programming Tool

12

910

ICCDATAICCCLKRESETVPP

ICP Connector Pin assignment

OSC_CLK

W2 W2

ICP ICP

7/28


2.6 I²C SERIAL COMMUNICATION

An external 8 Kb EEPROM memory with an I²C serial interface is connected to the I²C pins ofthe ST7 socket as shown in the following figure. The serial EEPROM may also be discon-nected and the I²C bus used for other communications.Figure 5. How to use the I²C Connection

2.7 SPI SERIAL COMMUNICATION

An external 4 Kb EEPROM memory with an SPI serial interface is connected to the SPI pinsof the ST7 socket as shown in the following figure. The serial EEPROM may also be discon-nected and the SPI bus used for other communications.Figure 6. How to use the SPI Connection

Using the On-board I²C EEPROM Using the I²C BUS

W7

Install all the jumpers on the I²C connector. Remove the jumpers and use left connector side.

SCLISDAI

U4

M24

C08

ST7 I²Cpins

W7

SCLISDAI I2

C

U4

M24

C08

ST7 I²CpinsI2

C

Install all the jumpers on the SPI connector. Remove the jumpers and use left connector side.

Using the On-board SPI EEPROM Using the SPI Bus

W 11

MISOSCK

SP

I

U5

M95

040

ST7 I²Cpins

MOSIPB3

W 11

MISOSCK

SP

I

U5

M95

040

ST7 I²Cpins

MOSIPB3

8/28


2.8 I/O PORT FUNCTIONALITY

All I/O port pins are accessible through external connectors ( TP1 for port A, TP2 for port Band TP3 for port C ).

2.8.1 Port A

The PA0 and PA1 pins are connected to the ICP connector using their alternate functions, IC-CCLK and ICCDATA.

The PA2 and PA3 pins are used to enable the U6 and U7 7-segment LED displays (useful formultiplexing).

The PA5 pin can be used to generate an external interrupt (ei0). It is connected to the groundvia the SW2 push-button switch .

The PA4 and PA6 pins alternate functions (SCLI and SDAI) are used for connecting an I²Ccommunication with the external I²C EEPROM.

PA7 is used to exercise the high sink I/O current capability through the High efficiency LED.Table 1. Port A Alternate Functions

2.8.2 Port B

This port is connected simultaneously to 8 LEDs and to the three 7-segment displays. It canbe used to display 8 bits of binary data.Table 2. Port B Alternate Functions

2.8.3 Port C

The PC0 pin can be connected to ground via the SW3 push-button in order to generate anexternal interrupt (ei1).

PA0 ICCCLK In Circuit Communication ClockPA1 ICCDATA In Circuit Communication DataPA2PA3PA4 SCLI I²C ClockPA5 RDI SCI outputPA6 SDAI I²C DataPA7 TDO SCI input

PB0 ICAP1_A Timer A Input Capture 1 PB1 OCMP1_A Timer A Output Compare 1PB2 ICAP2_A Timer A Input Capture 2PB3 OCMP2_A Timer A Output Compare 2PB4 MOSI SPI Master Out Slave In DataPB5 MISO SPI Master In Slave Out DataPB6 SCK SPI Serial ClockPB7 SS SPI Slave Select

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The PC1/OCMP1_B pin can be connected to a buzzer through the W10 jumper .

The PC2 pin is used to enable the output signal to the LEDs. A high level on PC2 enables thelogic states programmed by port B to be output on the 8 LEDs.

The PC3 pin is used to enable the U8 7-segment LEDs display (useful for multiplexing).

The PC4/AIN4 pin can be used through the W14 jumper as in analog input to measure thevoltage level of R13.

The PC5/AIN5 pin can be used through the W13 jumper as in analog input to measure theVREF voltage.Table 3. Port C Alternate Functions

2.9 JUMPER DESCRIPTIONS

2.9.1 W2 - Variable voltage enable/disable

This jumper allows you to disable the variable voltage and thus reduce the total power con-sumption of the board and extend battery life.

2.9.2 W3 - Board reference voltage selection

Refer to Section 2.3 POWER SUPPLY.

2.9.3 TP4 and TP5 - GND and VDD pins

These spare ground and VDD pins are for test purposes or for providing power to componentsin the wire-wrap area.

2.9.4 W6 - MCU power consumption

This jumper is only for connecting to the MCU power supply. Its main purpose is to allow youto measure the current consumption of the µC by connecting a DC-ammeter in series.

2.9.5 W4 and W5 - Source clock selection

Please refer to Section 2.4 Oscillation system.

2.9.6 W8 and W9 - External interrupts enable/disable

Those two jumpers allow you to disconnect the two push-buttons SW2 and SW3 from the PA5and PC0 pins respectively.

PC0 ICAP1_B / AIN0 Timer B Input Capture 1 Analog Input 0PC1 OCMP1_B / AIN1 Timer B Output Compare 1 Analog Input 1PC2 CLKOUT / AIN2 CPU Clock Out Analog Input 2PC3 ICAP2_B / AIN3 Timer B Input Capture 1 Analog Input 3PC4 OCMP2_B / AIN4 Timer B Output Compare 1 Analog Input 4PC5 EXTCLK_A / AIN5 Timer A External Clock Analog Input 5

10/28


2.9.7 W10 - Buzzer enable/disable

This jumper allows you to use the buzzer by connecting it to the PC1 pin.

2.9.8 TP1, TP2 and TP3 - Port connectors

These jumpers allow you to access all I/O ports.

2.9.9 W15 - LEDs enable/disable

This jumper is used to connect the LEDs to ground through the resistor network. It is recom-mended to remove the jumper from the board if this feature is not used.

2.9.10 W13 and W14 - Analog inputs enable/disable

These jumpers are for measuring the Vref analog voltage and the voltage through R13. Re-moving them will disable those two features (The measurement of the VDD voltage value andthe measurement of the current driven through the high efficiency LED).

2.9.11 W12 - High Sink I/O test enable/disable

This jumper lets you enable or disable the High efficiency LED.

2.9.12 W16, W17 and W18 - 7 seg Displays enable/disable

These jumpers allow you to enable/disable the three 7-seg displays (useful for multiplexing).

2.9.13 W1 - ICP Connector

Please refer to Section 2.5 ICP (In-Circuit Programming) connector.

2.9.14 W7 - I²C connector

Please refer to Section 2.6 I²C serial communication.

2.9.15 JP11 - SPI Connector

Please refer to Section 2.7 SPI serial communication.

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SOFTWARE DESCRIPTION

3 SOFTWARE DESCRIPTION

This part gives a short description of the whole program as a main routine that uses manyother functions and several drivers. The configuration of the microcontroller and also the con-figuration of option bytes is described first, followed by an overview of the main program struc-ture. Finally, we will provide a detailed description of how to use the board’s features.

3.1 OPTION BYTE CONFIGURATION

Option bytes are only accessed using In-Circuit Programming or an ST programming toolsuch as an EPB. In this case, the option bytes are configured as described below.

– Watchdog is configured to be enabled by software and to allow the MCU to enter Halt Mode (no reset on Halt).

– The LVD threshold is fixed to the medium value.

– Sector 0 size is 4 Kbytes.

– No program memory protection.

– Port C external interrupt mapping is configured as ei1.

– The clock security system is always on.

– Oscillator type is resonator oscillator.

– Oscillator range is between 8 and 16 MHz.

Table 4. Option byte configuration

EXTIT CSSOSC

TYPE1

OSC

TYPE0OSC

RNGE2OSC

RNGE1OSC

RNGE0PLL

OFF

1 0 0 0 0 1 1 1

WDGHALT WDG SW VD1 VD0 SEC1 SEC0 FMP R FMP W

0 1 0 1 1 1 0 0

12/28


3.2 MAIN MCU INITIALIZATION ROUTINE

This routine initializes the MCU as follows:

– MISCR (miscellaneous register): external interrupts trigger on falling edge, no slow mode and fCPU=8 MHz.

– Port A: PA7 (Driving the High efficiency LED) is an open drain output, PA6 & PA4 used by I²C as input without interrupt, PA5 (Push-button) used as floating input with interrupt, PA2 & PA3 (multiplexing 7-seg displays) as push-pull outputs.

– Port B: used as push pull output to display data.

– Port C: PC5 & PC4 as ADC alternate inputs, PC3 as push-pull output (multiplexing 7-seg displays), PC2 to select the LED bank (push-pull output), PC1 to drive the buzzer and PC0 as an input with interrupt (push-button).

3.3 COUNTERS AND USE OF TIMING RESOURCES

– Timer A is used as a real time clock that provides a precise time base for all program rou-tines. Timer A interrupt is enabled.

– Timer B is mainly used to drive the buzzer using PWM mode without interrupts.

3.4 INTERRUPT SERVICE ROUTINES

– Timer A interrupt: increment (circular buffer) several global counters used as time counters when the free running counter reaches the calculated value.

– AVD interrupt: saves the current mode when the power drops and, if we are in AVD mode, the last displayed digits are saved in the external I²C EEPROM using the I²C driver.

– ei1 Interrupt: this interrupt is used to wake-up the microcontroller from idle mode (HALT) and also it increments a circular variable used by the main program to enter the correspond-ing test.

– ei0 Interrupt: this interrupt is used to test concurrent and nested interrupts.

3.5 MAIN PROGRAM ROUTINE

The main program includes the initialization code and an endless loop that processes thepushbutton inputs. In fact, after initialization and enabling interrupts, the main program willcontinue running in an infinite loop and wait for an external interrupt to switch to one of thedemo routines: (LVD, AVD/CSS, High Current I/O, IAP, Concurrent/ Nested Interrupts).

By default the program is in Halt mode (to reducing power consumption).

Warning: Disconnect the battery from its socket when the Safe ST7 EvaluationBoard is not in use.

13/28


Figure 7. Main program flowchart

Begin

Disable all Interrupts

MCU Initialization

I²C Initialization

Safety procedure

Init Timer A

Disable RASS Keys

Enable all interrupts

“START” message “FINISH” message

LVD Demo

AVD Demo

IAP Demo

Nested IT DemoTest “MODE”

variable

: Program path/ PGM interrupt

Concurrent IT Demo

High Current Demo

Enter Halt Mode

This function is used for the AVD interrupt

14/28


3.6 OPERATING THE DEMOS

The flowcharts below provide a full description of all the tests and demos that you can run.Figure 8. Operations Flowchart (1)

Power-on the board / RESET

Display “START “ Light-on LED 0

Display the VDD voltage

Display a counter 000..999 Light-on LED2

Display " LVD " Light-on LED 1

End

MCU in a HALT state

Push The PGM button

No

Push The PGM button

Yes

HALT Mode

Push The PGM button

Push the DEMO button

Yes

Push The PGM button

No

Push The PGM button

Display "AVD CSS " Light-on LED 2

No

Yes

button

Yes

No

Yes

No

No

Push The PGM button

No

No

Push The PGM button

YesYes

No

Yes

To next figure

Light-on LED1

LoL fLow Voltage Detector Demo

AVD and CSS Demo

Push the DEMO

15/28


Figure 9. Operations Flowchart (2)

Display "HIO" Light-on LED 3

Display the current inside the High Efficiency LED Light-on LED 3

Light-on the high efficiency Led

Display "IAP" Light-on LED 4

Push the MODE Button

Push the DEMO button

Push The PGM button

No

No

Yes

Push The PGM button

No

Yes

Yes

From previous Figure

Push The PGM button

No

No

Display "SCORE 1" Light-on LED 4

Display " DONE " Light-on LED 4

Receive & Re-program

Score1 from the SPI E²PROM Send Score0 & Score1

to the SPI E²PROM Receive & Re-program

Score0 from the SPI E²PROM

Test XFlash memory

Display "TRANSFER" Light-on LED 4

Display "SCORE 0" Light-on LED 4

Score 1Score 0

First Time

Push The PGM button

To next Figure

Yes

No

Yes

High I/O Current Demo

In-Application Programming Demo

16/28


Figure 10. Operations Flowchart (3)

Display " CONCURRENT IT " Light-on LED 5

Wait End of score Light-on LED 5

Display " FINISH " Light-on LED 7

End

From previous Figure

End of the message

Push The PGM button

No

No

Light-on LED 5

Yes

Push The PGM button

Play music Score Light-on LED 5

End of The Score Push The DEMO button

Yes

Display " NESTED IT " Light-on LED 6

Yes

No

No

Display a lighting Sequence on LEDs

Yes

Push The PGM button

End of the Light-on LED 6

Push The PGM button

No

Play music Score Light-on LED 6

End of The Score Push The DEMO button

No

Display a lighting Sequence on LEDs

Yes

Yes

Yes

Concurrent Interrupts Demo

message

Yes

No

IT1

IT0

Nested Interrupts Demo

17/28


3.6.1 Running the LVD Demo

In LVD Demo state (see Figure 11), the user can switch between the two positions of W3 asdescribed in Section 2.3.

If the power goes below the LVD level, the microcontroller enters RESET state. At power-on,the program enters LVD demo mode (because an LVD reset was detected) and displays theVDD voltage on the 7-seg display.

3.6.1.1 LVD Demo Description

The program reads in a fixed 2.4V reference voltage (VREF) via the 10-bit ADC channel, doessome arithmetic to convert the digital value it has read to a voltage level and finally displaysthe main voltage of the board (VDD) in Volts on the three 7-segment LEDs.

Note: X is the converted digital value of VREF (2.4 Volts) and 3FF is the digital value of VDD,So:

Figure 11. LVD Demo Overview

The W3 jumper must be moved to the right to select the variable power supply. If the RV1trimmer is turned completely clockwise, the board is powered by 5.6 Volts. If the trimmer isturned counter-clockwise the VDD value will decrease until we reach the LVD threshold (VIT-),at which point the microcontroller enters reset mode.

VDD 2.4 3FFX

-----------×=

press to reset

Battery

ST72F264

Potentiometer

LED1

move the jumper to right

onoff

SAFE ST7

Push to run the Demo

press until LED1 lights-on

EVALUATION BOARD

18/28


In power-on, if the trimmer is turned clockwise, the device will leave reset state and we cansee the VIT+ threshold on the display.

Note: the VIT- reference value for a voltage drop is lower than the VIT+ reference value forpower-on in order to avoid parasitic reset when the microcontroller starts running and sinkscurrent on the supply (hysteresis).

3.6.2 Running the AVD Demo

In Auxiliary Voltage Detector & Clock Security System Demo state (see Figure 12), the 7-segdisplay shows a counter that increments from 000 to 999.

To test the AVD capability:

– Disconnect the battery or decrease the VDD voltage using the power trimmer until the MCU enters RESET state.

– Then, supply the board with the right voltage.

– You will see that the counter does not restart at 000, but resumes counting from the last dis-played value before shut-down.

3.6.2.1 AVD Demo Description

For system integrity management, in addition to the LVD feature, the Safe ST7 EvaluationBoard has an auxiliary voltage detector (AVD) with interrupt capability. In case of a drop involtage, the AVD interrupt acts as an early warning, allowing software to shut down safely be-fore the LVD resets the microcontroller. The AVD works closely with the LVD and functionsonly if the LVD is enabled through option byte (see “Option byte configuration” on page 12).

19/28


Figure 12. AVD Demo Overview

In case of power drop, and before going into reset state, the AVD interrupt will save the lastdisplayed value in the external EEPROM (M24C08) using the I²C protocol. On power-on, thesoftware checks if the last reset was made by the LVD, if this is the case, it downloads the pre-viously saved value from the external EEPROM to RAM memory in order to resume countingas normal.

To cause a voltage drop, we can choose between two solutions as shown in the Figure 12.Thefirst method consists of moving the W3 jumper to the right, then decreasing the main voltageby turning the RV1 trimmer counter-clockwise. The second method consists of moving the W3jumper to the left so that we will have a 5-Volt reference value, and then disconnecting the bat-tery.

3.6.3 Running the CSS Demo

To run this demo, we have to be in the same state as in the AVD demo see “Running the AVDDemo” on page 19.

Once the main program runs at 8 MHz, Timer A is configured to manage the counting opera-tion displayed on the three 7-segments LEDs.

To test the CSS capability:

– Disconnect the oscillator by removing the W4 and W5 jumpers.

– You will see the frequency decreases significantly but that the counter still working.

press to reset

Battery

ST72F264

Potentiometer

LED2

move the jumper to right

onoff

press to reset

Battery

ST72F264

LED2

move the jumper to left

Disconnect the battery

press until LED2lights-on Push to

run the Demo

press until LED2 lights-on Push to

run the Demo



20/28


3.6.3.1 CSS Demo Description

The clock security system (CSS) embedded in the ST72F264 family of microcontrollers, pro-tects the device against problems occurring to the main clock. To allow you to integrate secu-rity features in your application, it performs clock filter control and generates an interrupt incase of clock problems, while switching to an internal safe oscillator to allow the software tokeep running at a reduced speed. The safe oscillator of the CSS block is a low frequencyback-up clock source (around 3 Mhz). Figure 13. CSS Demo Overview

If the clock signal disappears, which you can provoke by disconnecting the two jumpers asshown in Figure 13, the safe oscillator delivers a low frequency clock signal (around 3MHz) fora safe oscillator period which allows the ST7 to save any critical data or perform any kind ofemergency operations while the CPU is still running.

The ST7 clock source switches back from the safe oscillator automatically if the original clocksource recovers. You can simulate this by replacing the clock jumpers. For more details referto Section 2.4 Oscillation system.

3.6.4 Running the High I/O current demo

This demo uses the example of a high efficiency LED to provide a visible result: its relative lu-minosity increases linearly with the forward current, which reaches more than 50mA at only 3Volts.

The program measures the value of the current in the LED using ADC analog input channel 4and at the same time it displays the result on three 7-segment LEDs (units in mA).


press to reset

Battery

ST72F264

LED2


Disconnect the two clock jumpers

Push to

run the Demo


21/28


To vary the forward current, we have to move the RV2 trimmer position as shown in Figure 14

You can verify the current value for yourself by connecting a serial ammeter to W12.Figure 14. High Sink I/O Demo Overview

3.6.4.1 High Sink Demo Description

This demo shows how the high sink outputs can be used and how to measure the current de-livered by any of the high sink outputs on Port A. In addition to standard I/O ports which sinkand sources a maximum (absolute rating) output current of 25mA, most ST7s include Highsink I/Os that can sink a current (absolute rating) output of up to 50mA. This allows you todrive any type of high power device directly without needing expensive external circuitry.

3.6.5 Running the IAP demo

This demo consists of re-programming XFLASH sector 1 using the In-Application Program-ming. To show this, it reprograms one piece of music (64 Bytes) by another one using the SPIcommunication protocol with the external M95040 4Kb SPI EEPROM memory.

The demo software includes an IAP_driver that will be copied to the RAM area to execute thedemo. It programs 16 bytes at a time.

For more details about XFLASH In-Application Programming refer to the ST7 FLASH Pro-gramming Reference manual.

As shown in Figure 15, you enter the IAP demo by pushing down the PGM button until LED4lights-up and the “IAP” message appears. Then you must push the DEMO button. During thistime the device will be updated and when this is finished a “DONE” message will appear.


press to reset

Battery

ST72F264

LED3


- + Push to run the Demo


22/28


Note: If you don’t want to enter this mode, you must push the PGM button again to jump di-rectly to the next demo.

Note: This demo only runs the software that downloads the musical sequence from the ex-ternal EEPROM to the XFLASH device. This music data can be output on the buzzer. In orderto listen to the music and verify that the data has been changed by IAP, you have to run thenested & concurrent interrupts demos.Figure 15. IAP Demo Overview

3.6.5.1 IAP Demo Description

The ST72F26x microcontroller family has a single voltage extended Flash (XFLASH) area thatcan be electrically erased and programmed either on a byte-by-byte basis or up to 32 bytes inparallel. In-Application Programming (IAP) allows you to update program memory contentswhen the device is already plugged on the application board, at minimum cost in terms ofadded components and board area impact.

This programming mode uses an IAP driver program which has been previously programmedin sector 0. This method is fully controlled by user software. This allows it to be adapted to theuser application (user-defined strategy for entering programming mode, choice of communi-cations protocol used to fetch the data to be stored).

RAM Mapping

0xA0 to 0xA1: XFLASH start address (2 bytes)

0xA2 to 0xB2: 16-byte RAM buffer.

press to reset

Battery

ST72F264

LED4

keep the jumper to left

press until LED4lights-on

Push to run the Demo


23/28


0xB2 to 0xCE: IAP_driver storage area, (used only while the demo is running)

Sector1 Mapping (Reprogrammable Area)

0xE000 to 0xE00F: 16 spare bytes for testing

0xE010 to 0xE04F: (64 bytes) Music score1 (Software reprogrammable bytes)

0xE050 to 0xE08F: (64 bytes) Music score 2

0xE090 to 0xE14F: All other constantsFigure 16. IAP Demo flowchart

3.6.6 Running the Nested & Concurrent Interrupts demo

Most ST7 microcontrollers have two different interrupt management modes. The first is calledconcurrent mode and does not allow an interrupt to be interrupted, unlike the nested modewhere a software priority is given to each interrupt.

Begin

Test 0xE000 content

Display "TRANSFER"

First time the chip is plugged in

Init SPI

Send Score1&2 to M95040

SPI Disable

Using IAP write "1" to 0xE000

End

Init SPI

Receive next 16 bytes of Score1 (2) from M95040

SPI Disable

Using IAP write "2" (1) to 0xE000

Else 0xE010..0xE04F contents Score0 (or 1)

Repeat 4 times

Program 16 bytes of Score1 (2) to the right addresses

Display "SCORE0" (or "SCORE1")

24/28


3.6.6.1 Nested & Concurrent Interrupts Demo DescriptionFigure 17. Interrupts Demo Overview

As shown in Figure 17 this demo is divided into two parts: The first one runs concurrent inter-rupts while the second uses nested interrupts.

The IT0 and IT1 interrupt service routines are assigned to external interrupt vectors ei0 andei1. You can trigger the interrupts directly by pressing the two push-buttons shown in Figure17:

IT1: outputs a piece of music (previously downloaded in the IAP demo) on the buzzer.

IT0: displays a lighting sequence on LEDs.

In the first demo (Concurrent Interrupts), all the interrupts have the same priority level, so theinterrupt with the highest hardware priority will be serviced (in this case it is ei0).

In this demo, you have to push the PGM button in order to trigger the IT1 routine, then pushingthe DEMO button, IT0 won’t interrupt the IT1 routine and you have to wait for the end of musicbefore the LEDs light up in sequence.

To run the nested interrupt demo the board must be in the state shown in Figure 17, then if youpush the PGM button, it will trigger the IT1 interrupt routine (music output). Before the end ofthe music you have to push the DEMO button in order abort the IT1 routine and service the IT0routine. When the program returns from IT0, it resumes playing the music from the pointwhere it was interrupted.

press to reset

Battery

ST72F264

LED5


(1) Press to run IT1


Buzzer

press to reset

Battery

ST72F264

LED6




Buzzer

Nested Interrupt DemoConcurrent Interrupt Demo



25/28

Appendix 1: Safe ST7 Evaluation Board SCHEMATIC

4 APPENDIX 1: SAFE ST7 EVALUATION BOARD SCHEMATIC

CD1

100nF

C1

100µF

1 3

2

V V

GNDIN OUT

U1L7805D1

1N4004

D21N4004

RV110k

R4

1k

R54.7k

T12N2222

VCC

R24.7kC2

100µFCD2100nF

LD1

POWER

Z2

5V6

VCC

12

J1

BT1

R1470

Z12V4

123

W3

POWER SELECT

3

21

84

U2A

TS912

VREF

W2

PA0PA1PA2PA3PA4PA5PA6PA7

PB0PB1PB2PB3PB4PB5PB6PB7

PC0PC1PC2PC3PC4

12345678

TP1

12345678

TP2

12

TP4

VCC

12

TP5

GND

VCC

123456

TP3

PC5

26/28


R64.7k

SW1RESET

VCC

CD3100nF

XT1

4MhzC522pF

C422pF

R1027k

R927k

R11

100R12

100

VCC

VCC

VCC

CD7100pF

CD8100pF

PB6

PB4

PB5

12345678910

W1

ICP

VCCR310k

RESET

LD3

LD4

LD5

LD6

LD7

LD8

LD9

LD10

PB0

PB1

PB2

PB3

PB4

PB5

PB6

PB7



T3BC547

VCCCD4

100nFR74.7k

SW2DEMO

VCC

CD5100nF

R84.7k

SW3PGM CD6

100nF

EI0 EI1

R1310

LD2

VPP

OSC1

T2

BC547

ICCCLK/PA0 29

ICCDATA/PA1 28

PA2 27

PA3 26

SCLI/PA4 23

RDI/PA5 22

SDAI/PA6 21

TDO/PA7(HS) 20PB0/ICAP1_A13

PB1/OCMP1_A12

PB2/ICAP2_A11

PB6/SCK5

PB4/MOSI7

PB5/MISO6

PB3/OCMP2_A10

PB7/ SS4

AIN1/OCMP1_B/PC1 18

AIN2/MCO/PC2 17PC3/ICAP2_B/AIN316

PC4/OCMP2_B/AIN415

PC5/EXTCLK_A/AIN514

OSC12

OSC23

RESET1

VPP/TEST 30

VDD 32

NC8

NC9

VSS 31

AIN0/ICAP1_B/PC0 19

NC 24

NC 25

U3

ST72F264

123

W5

123

W4

R161k

W16 R15

4.7kPA2

W15

Leds enable

R14

4.7kPC2

T4BC547

R181k

W17 R17

4.7kPA3

VCC

W14

W13VREF

BZ1

Buzzer

W10

W6 IDDVCC

W9

W8

SS1

D5

Q2

W 3

HOLD 7

C6

VC

C8

VSS

4

U5

M95040

PC2

E0 1

E1 2

E2 3

SDA5

SCLK6

WC 7

VC

C8

VSS

4

U4

M24C08

VPP

ICCCLK

ICCDATA

VPP

ICCDATA

PA3

PA2

ICCCLK

W12

23456789

1

RS1

1k

1 23 4

W7

I2C

76421

1095

3 8

U8


76421

1095

3 8

U6

76421

1095

3 8

U7

T5BC547

R201k

W18 R19

4.7kPC3

PB7

PB6

PB5

PB4

PB3

PB2

PB1

PB0

PC3

PC5

PC4

PC3 PC2

PC1

PC0

PA7

PA6

PA5

PA4

PA3

PA2

1 23 45 67 8

W11

SPI

PB3

C3

100pF

PA0

PA1

PA4

PA6

PA1

PA0

RV2

I/O Test

27/28


THE SOFTWARE INCLUDED IN THIS NOTE IS FOR GUIDANCE ONLY. STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM USE OF THE SOFTWARE.

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequencesof use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is grantedby implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subjectto change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are notauthorized for use as critical components in life support devices or systems without the express written approval of STMicroelectronics.

The ST logo is a registered trademark of STMicroelectronics

�2002 STMicroelectronics - All Rights Reserved.

Purchase of I2C Components by STMicroelectronics conveys a license under the Philips I2C Patent. Rights to use these components in an I2C system is granted provided that the system conforms to the I2C Standard Specification as defined by Philips.

STMicroelectronics Group of CompaniesAustralia - Brazil - Canada - China - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan

Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A.

http://www.st.com

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