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Atmega8515(l) – Rainbow Electronics ATmega8515L User Manual

Page 172

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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