atmega3250v-8auatmega325v-8ai ATMEL Corporation, atmega3250v-8auatmega325v-8ai Datasheet - Page 260

• Manufacturer Part Number: atmega3250v-8auatmega325v-8ai
• Description: Atmega3250 8-bit Microcontroller With In-system Programmable Flash
• Manufacturer: ATMEL Corporation

260
ATmega325/3250/645/6450
Rdloop:
Return:
Do_spm:
Wait_spm:
Wait_ee:
call Do_spm
; re-enable the RWW section
ldi
call Do_spm
; read back and check, optional
ldi
ldi
subi YL, low(PAGESIZEB)
sbci YH, high(PAGESIZEB)
lpm
ld
cpse r0, r1
jmp
sbiw loophi:looplo, 1
brne Rdloop
; return to RWW section
; verify that RWW section is safe to read
in
sbrs temp1, RWWSB
ret
; re-enable the RWW section
ldi
call Do_spm
rjmp Return
; check for previous SPM complete
in
sbrc temp1, SPMEN
rjmp Wait_spm
; input: spmcrval determines SPM action
; disable interrupts if enabled, store status
in
cli
; check that no EEPROM write access is present
sbic EECR, EEWE
rjmp Wait_ee
; SPM timed sequence
out
spm
; restore SREG (to enable interrupts if originally enabled)
out
ret
spmcrval, (1<<RWWSRE) | (1<<SPMEN)
looplo, low(PAGESIZEB)
loophi, high(PAGESIZEB)
r0, Z+
r1, Y+
Error
temp1, SPMCSR
spmcrval, (1<<RWWSRE) | (1<<SPMEN)
temp1, SPMCSR
temp2, SREG
SPMCSR, spmcrval
SREG, temp2
; If RWWSB is set, the RWW section is not ready yet
;init loop variable
;not required for PAGESIZEB<=256
;restore pointer
;use subi for PAGESIZEB<=256
2570L–AVR–08/07