Posted on October 25, 2017 at 07:55Hi!
If you translate this bit of Forth into assembly, then here is how to do it.
Note that '\ ..' and '( .. )' are comments. Data is passed through the data stack, and you can probably keep it in registers when coding it in assembly.
\ STM8S option setting words
\ refer to github.com/TG9541/stm8ef/blob/master/LICENSE.md
\ store char c to (a), inverted value to (a+1)
: CN! ( c a -- )
2DUP C! SWAP NOT SWAP 1+ C! ;
\ unlock write protection, store option byte
: OPT! ( c a -- )
FLASH_CR2 DUP C@ $80 OR SWAP CN! \ unlock option bytes
ULOCK CN! LOCK \ unlock EEPROM, write c to (a) ;
\\ ULOCK and LOCK from forth.asm:
; LOCK ( -- )
; Lock EEPROM (STM8S)
HEADER LOCK 'LOCK'
LOCK:
BRES FLASH_IAPSR,#3
RET
HEADER ULOCK 'ULOCK'
ULOCK:
MOV FLASH_DUKR,#0xAE
MOV FLASH_DUKR,#0x56
1$: BTJF FLASH_IAPSR,#3,1$ ; PM0051 4.1 requires polling bit3=1 before writing
RET
