stm8s/eeprom_blockprog.c

70 lines
2.0 KiB
C

/** library to program EEPROM using block programming
* @file
* @author King Kévin <kingkevin@cuvoodoo.info>
* @copyright SPDX-License-Identifier: GPL-3.0-or-later
* @date 2021
* @warning functions need to be put in and run from RAM (because block programming is used)
*/
// RAM code-putting from https://lujji.github.io/blog/executing-code-from-ram-on-stm8/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdbool.h> // boolean types
#include "stm8s.h" // STM8S definitions
#include "eeprom_blockprog.h" // own definitions
// start address of EEPROM
#define EEPROM_ADDR 0x4000
// block size from low-density devices (including STM8S103)
#define DATA_BLOCK_SIZE 64U
#pragma codeseg RAM_SEG
bool eeprom_blockprog(const uint8_t* data, uint16_t length)
{
if (0 == length) {
return true; // nothing to do
}
if (!data) {
return false; // data missing
}
if (0 != (length % DATA_BLOCK_SIZE)) {
return false; // we can only program whole blocks
}
// disable DATA (e.g. EEPROM) write protection
// don't check if it is locked this it does not save that much time and uses memory)
FLASH_DUKR = FLASH_DUKR_KEY1;
FLASH_DUKR = FLASH_DUKR_KEY2;
// don't verify if unlock succeeded to save memory
// if (!(FLASH_IAPSR & FLASH_IAPSR_DUL)) { // un-protecting failed
// return false;
// }
// program data
uint8_t* eeprom = (uint8_t*)(EEPROM_ADDR);
while (length) {
// enable standard block programming
FLASH_CR2 |= FLASH_CR2_PRG;
FLASH_NCR2 &= ~FLASH_NCR2_NPRG;
// program block
for (uint8_t i = 0; i < DATA_BLOCK_SIZE; i++) {
*(eeprom++) = *(data++);
}
length -= DATA_BLOCK_SIZE;
// wait until program completed
while (FLASH_CR2 & FLASH_CR2_PRG);
// check if programming failed
// we don't check for WR_PG_DIS (while checking EOP) because EEPROM isn't (and can't be) write protected
if (!(FLASH_IAPSR & FLASH_IAPSR_EOP)) {
FLASH_IAPSR &= ~FLASH_IAPSR_DUL; // re-enable write protection
return false;
}
}
FLASH_IAPSR &= ~FLASH_IAPSR_DUL; // re-enable write protection
return true;
}