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ST7 CHECKSUM SELFCHECKING CAPABILITY

s

Generate the new .s19 file.

s

Program the FLASH using the EPB Programming Board and fill the unused memory with the

same opcode as before ($83 in our example) using the Edit, Fill area menu in STVisual

Programmer software (STVP7).

2.2 ROM

For the ROM, the principle is the same, but you have to specify the content of the unused

bytes in the program memory.

In order that the stored checksum matches the calculated one, the unused bytes have to be

the same. Using the windows programmer (STVP7), fill the unused bytes with a particular op-

code (the trap code for instance: 83h), and then save this new complete .s19 file, replacing the

previous one. Otherwise fill the unused bytes directly in the code with using assembly lan-

guage REPEAT...UNTIL directives. Refer to the “ST7 Assembler-Linker user manual” for

more information on ST7 assembly directives.