AN2737

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The firmware implements byte, word, and block programming features offered by the STM8

Flash program memory and data EEPROM.

Block programming has to be executed from the RAM memory. Consequently, at the

beginning of the code, the Flash function section is copied to the RAM memory. To copy and

link some code to the RAM memory using the Cosmic linker, the steps below must be

followed:

●

Define the section to be linked in RAM as a movable segment using the linker option ‘-

ic’.

●

At the begining of the code, execute the ‘_fctcpy’ function which copies the code from

the Flash to the RAM memory.

For more details about movable codes, please refer to the COSMIC “C Cross Compiler

User’s Guide for ST Microelectronics STM8” available on www.cosmicsoftware.com.

1.3

Read and write command examples

The firmware allows read or write operations in the Flash program memory (from address

8000h up to 27FFFh) or in the data EEPROM (from address 4000h up to 47FFh) memory of

the STM8.

Current and random options are available for both read and write operations:

●

The random command allows data to be read/writen at a specific address.

●

The current command allows data to be read/writen at the current address pointer. The

default current address pointer value (after reset) is 4000h (start of the data EEPROM).

So, for example, after writing (or reading) 10 bytes to the memory, the current address

pointer value becomes 400Ah. The address is passed on 3 bytes with the most

significant bit (MSB) first.

Note:

The firmware follows standard serial I²C EEPROM protocol rules.

Before starting, the firmware example must be loaded with STVD and executed using the

run command. The evaluation board LCD displays a welcome message ‘STM8 IAP-I2C

Demo’.

1.3.1

Packet description

START: Start signal which is generated by the master.

ADD SLV DEVICE-W: Slave device address which is sent by the master with the direction

bit set to write.

ACK-S: Acknowledge signal which is generated by the slave.

ACK-M: Acknowledge signal which is generated by the master.

ACKF: Acknowledge failure or ‘no acknowledge’ signal which are both generated by the

master. A ‘no acknowledge’ signal is generated by the master to notify the slave device that

the last read byte has been correctly received which marks the end of a read operation.

STOP: Stop signal which is generated by the master.