Atmega8515(l) – Rainbow Electronics ATmega8515L User Manual
Page 172

172
ATmega8515(L)
2512A–AVR–04/02
; 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
spmcrval, (1< rcall 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 spmcrval, (1< rcall Do_spm ; re-enable the RWW section ldi spmcrval, (1< rcall 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 rjmp 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: in temp1, SPMCR sbrs temp1, RWWSB ; If RWWSB is set, the RWW section is not ; ready yet ret ; re-enable the RWW section ldi spmcrval, (1< rcall Do_spm rjmp Return Do_spm: ; check for previous SPM complete Wait_spm: in temp1, SPMCR sbrc temp1, SPMEN rjmp Wait_spm ; input: spmcrval determines SPM action ; disable interrupts if enabled, store status in temp2, SREG cli ; check that no EEPROM write access is present Wait_ee: sbic EECR, EEWE rjmp Wait_ee ; SPM timed sequence out SPMCR, spmcrval spm