283
2467S–AVR–07/09
ATmega128
; transfer data from RAM to Flash page buffer
ldi
looplo, low(PAGESIZEB);init loop variable
ldi
loophi, high(PAGESIZEB);not required for PAGESIZEB<=256
Wrloop:
ld
r0, Y+
ld
r1, Y+
ldi
spmcsrval, (1<<SPMEN)
call
Do_spm
adiw
ZH:ZL, 2
sbiw
loophi:looplo, 2
;use subi for PAGESIZEB<=256
brne
Wrloop
; execute page write
subi
ZL, low(PAGESIZEB)
;restore pointer
sbci
ZH, high(PAGESIZEB)
;not required for PAGESIZEB<=256
ldi
spmcsrval, (1<<PGWRT) | (1<<SPMEN)
call
Do_spm
; re-enable the RWW section
ldi
spmcsrval, (1<<RWWSRE) | (1<<SPMEN)
call
Do_spm
; read back and check, optional
ldi
looplo, low(PAGESIZEB);init loop variable
ldi
loophi, high(PAGESIZEB);not required for PAGESIZEB<=256
subi
YL, low(PAGESIZEB)
;restore pointer
sbci
YH, high(PAGESIZEB)
Rdloop:
lpm
r0, Z+
ld
r1, Y+
cpse
r0, r1
jmp
Error
sbiw
loophi:looplo, 1
;use subi for PAGESIZEB<=256
brne
Rdloop
; return to RWW section
; verify that RWW section is safe to read
Return:
lds
temp1, SPMCSR
sbrs
temp1, RWWSB
; If RWWSB is set, the RWW section is not ready
yet
ret
; re-enable the RWW section
ldi
spmcsrval, (1<<RWWSRE) | (1<<SPMEN)
call
Do_spm
rjmp
Return
Do_spm:
; check for previous SPM complete
Wait_spm:
lds
temp1, SPMCSR
sbrc
temp1, SPMEN
rjmp
Wait_spm
; input: spmcsrval determines SPM action
; disable interrupts if enabled, store status
in
temp2, SREG
cli
; check that no EEPROM write access is present