STM8L052C6 - Unable to write to flash and EEPROM, Tries exceeded

[VladimirGaristov]

Trying to write data to the flash or EEPROM of STM8L052C6 results in Tries exceeded error message. Writing to option bytes and RAM works fine and so does reading from all memories. I'm using an unofficial clone of ST-LINK V2. Flashing the same chip with the same st-link works fine with STVP on Windows. The read protection is disabled and I've tried flashing raw binary and intel hex.

[tcfkat]

Hello Vladimir, I had exactly the same problem yesterday! Sadly I have no MS-DOS machine here to cross-check. It took me hours to fix the problem. It was a false FLASH block size declaration in stm8.c! Change the following, beginning in line 375:

{
        .name = "stm8l052c6",
        .ram_start = 0x0000,
        .ram_size = 2*1024,
        .eeprom_start = 0x1000,
        .eeprom_size = 256,
        .flash_start = 0x8000,
        .flash_size = 32*1024,
        .flash_block_size = 128, // was WRONG!
        .option_bytes_size = 13, // was ZERO!
        .read_out_protection_mode = ROP_STM8L, // was ROP_UNKNOWN
        REGS_STM8L
},

recompile and it should work. Furthermore I changed at the beginning the value of CLK_CKDIVR:

// Note: FLASH_NCR2 not present on stm8l
#define REGS_STM8L { \
        .CLK_CKDIVR = 0x50c0,  \
        .FLASH_PUKR = 0x5052,  \
        .FLASH_DUKR = 0x5053,  \
        .FLASH_IAPSR = 0x5054, \
        .FLASH_CR2 = 0x5051,   \
        .FLASH_NCR2 = 0x0000,   \

but a little bit unsure here, as I am new to STM8.

Finally I updated the firmware of my ST-LINK V2 clone to version V2J38S7 using a JAR-file from the ST website. This is not related to the problem here, but better safe than sorry ...

LAST EDIT: Formatting ok now

[andyboeh]

Thanks for the fix @tcfkat! I ran into the same problem and it's working properly now!

[spth]

Have option bytes and read-out-protection also been tested with this change? @andyboeh : did you also make the change in REGS_STM8L tcfkat mentioned, or did it work with just the change to the flash block size?

[andyboeh]

I did an unlock and it worked - prior to that, flashing was not possible.

No, I only changed the three lines in stm8.c regarding flash_block_size and so on, nothing more. Brand new ST-Link v2 clone with the default firmware.

I can test on further devices, but this is going to take some time (in the order of weeks I suppose, I have to develop the firmware first).

[VladimirGaristov]

Thank you @tcfkat, I can reconfirm that this fixes the issue. Sorry for taking so long to respond, I had put my project on hold for a while. May I suggest you fork and make a pull request? EDIT: Also you are right, according to the datasheet and reference manual, CLK_CKDIVR should be 0x50c0.

[qiwenmin]

@tcfkat thank you! This fixes the issue. I tried with the stlinkv2 on stm8l052c6t6.

[spth]

Thanks for the fix and confirmations. I've now updated the repo accordingly.