Hello,
KnightOS's flash writing routines are not working, and I need some help with them. Here is the code, any help would be appriciated:
Code:
Edit: x.x Figured it out
The test data I was passing in was setting bits, not resetting them
KnightOS's flash writing routines are not working, and I need some help with them. Here is the code, any help would be appriciated:
Code:
WriteFlashByte:
push hl
push af
ld bc, ProgramRoutineEnd - ProgramFlashRoutine
call AllocateExecutableMem ; Allocates executable RAM, accepts BC as size, outputs hl is pointer to free RAM
ex hl, de
push de
ld hl, ProgramFlashRoutine
ldir
pop de
pop af
pop hl
ex hl, de
ld bc, WriteFlashRet
push bc
;di
;halt
jp (hl)
WriteFlashRet:
ret
ProgramFlashRoutine:
; a = value, hl = address
; Flash program sequence
; This is being done according to how the datasheet says it should be done.
; The standard interrupt must not trigger during this sequence or the flash chip
; will not get the write command.
; At 6MHz, one clock cycle will be 167ns
; At 15MHz, one clock cycle will be 67ns
ex hl, de
push af
push hl
di
; reset bus (not needed by the books)
;ld a, 0F0h
;ld (4000h), a
; First bus cycle---unlock
ld a, 0AAh
ld (4AAAh), a
; Second bus cycle---unlock
ld a, 55h
ld (4555h), a
; Third bus cycle---write command
ld a, 0A0h
ld (4AAAh), a
; Fourth bus cycle---program data
pop hl
pop af
ld (hl), a
; Wait for data to be good
; "During the Embedded Program Algorithm, an attempt to read the devices will
; produce the complement of the data last written to DQ7. Upon completion of the
; Embedded Program Algorithm, an attempt to read the device will produce the
; true data last written to DQ7"
; "DQ5 will indicate if the program or erase time has exceeded the specified
; limits (internal pulse count). If this occurs, reset the device with command
; sequence."---Fujitsu documentation
programWaitLoop:
ld b, a
ld a, 0FDh ; This checks for the CLEAR key.
out (1), a ; If pressed, it aborts.
in a, (1)
cp 0BFh
jr z, abortProgram
xor (hl)
bit 7, a
ld a, b
jr z, programDone
bit 5, (hl)
jr z, programWaitLoop
abortProgram:
ld a, 0F0h
ld (4000h), a
ret
programDone:
ei
ret
ProgramRoutineEnd:Edit: x.x Figured it out
The test data I was passing in was setting bits, not resetting them
