Hi, I'm using the STM8S001J.
I don't use libraries, but reading the datasheet I discovered that writing the option bytes is very similar to writing Eeprom, so I realized a couple of simple functions. You can compare it with yours to verify if it's the same thing. This is the function I wrote to program an option byte:
void OptionWrite(char *addr, unsigned char data) // write a byte to OPTIONS (read=EarRead)
{
FLASH_DUKR = 0xAE; // unlock the EEprom
FLASH_DUKR = 0x56; //
FLASH_CR2 |= 0x80; // unlock the OPTION (set bit OPT)
FLASH_NCR2 &= 0x7F; // (clear bit NOPT)
*addr = data; // write data
while((FLASH_IAPSR & 0x04) == 0); // wait for EOP (end-of-programming) set
FLASH_IAPSR = 0x00; // Write protect the EEPROM clearing DUL bit
}
and this is to read from it (it's the same as for the Eeprom):
unsigned char EarRead(char *addr) // read a byte from EEprom
{
BYTE data;
data = *addr; // read data
return data;
}
Finally, this is an example of how to use it:
mc = EarRead((char *)0x4803); // read option byte OPT2 from EEprom
if(mc != 0x03) // if option programming different from requested one
{
OptionWrite((char *)0x4803, 0x03); // write OPT2 (0x4803)
OptionWrite((char *)0x4804, 0xFC); // write NOPT2 (0x4804)
}
Every option byte must be written in direct and complemented form. In this case I wanted the OPT2 = 0x03, so I wrote 0x03 in OPT2 and 0xFC in NOPT2.
I used the OptionWrite just as an experiment, so it's NOT fully tested, but it worked.
Sorry for confused tabs/indent in listings, but it's impossible to edit them after a copy/paste in the "code" box.
Any confirmation by the STM8 gurus will be highly appreciated. Thanks.
