EEPROM Read/Write for ATMega168

eeprom.asm

.INCLUDE "m168def.inc"
.LIST
.CSEG
.ORG 0

jmp main

.DEF addr1 = R30
.DEF addr2 = R31
.DEF data = R29

; Read from addr(r30:r31) put into r29
read:
	; Wait for completion of previous write
	sbic EECR, EEPE
	rjmp read
	; Set up address (r30:r31) in address register
	out EEARH, R30
	out EEARL, R31
	; Start eeprom read by setting EERE
	sbi EECR, EERE
	in R29, EEDR
	ret

; Write r29 to addr (r30:r31)
write:
	; Wait for completion of previous write
	sbic EECR, EEPE
	rjmp write
	; Set up address (r30:r31) in address register
	out EEARH, R30
	out EEARL, R31
	; Write data (r29) to register
	out EEDR, R29
	; Write logical one to EEMPE
	sbi EECR, EEMPE
	; Start eeprom write by setting EEPE
	sbi EECR, EEPE
	ret

main:
	ldi addr1, 0x00

	ldi addr2, 0x00
	ldi data, 0xF1
	call write
	
	ldi addr2, 0x01
	ldi data, 0xE2
	call write

	ldi addr2, 0x00
	call read

	jmp loop

loop:
	NOP
	jmp loop