ATMEGA8L ATMEL [ATMEL Corporation], ATMEGA8L Datasheet - Page 20

• Manufacturer Part Number: ATMEGA8L
• Description: 8-bit AVR with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

20
ATmega8(L)
The following code examples show one assembly and one C function for writing to the
EEPROM. The examples assume that interrupts are controlled (for example by dis-
abling interrupts globally) so that no interrupts will occur during execution of these
functions. The examples also assume that no Flash boot loader is present in the soft-
ware. If such code is present, the EEPROM write function must also wait for any
ongoing SPM command to finish.
Assembly Code Example
C Code Example
EEPROM_write:
void EEPROM_write(unsigned int uiAddress, unsigned char ucData)
{
}
; Wait for completion of previous write
sbic EECR,EEWE
rjmp EEPROM_write
; Set up address (r18:r17) in address register
out EEARH, r18
out EEARL, r17
; Write data (r16) to data register
out EEDR,r16
; Write logical one to EEMWE
sbi EECR,EEMWE
; Start eeprom write by setting EEWE
sbi EECR,EEWE
ret
/* Wait for completion of previous write */
while(EECR & (1<<EEWE))
/* Set up address and data registers */
EEAR = uiAddress;
EEDR = ucData;
/* Write logical one to EEMWE */
EECR |= (1<<EEMWE);
/* Start eeprom write by setting EEWE */
EECR |= (1<<EEWE);
;
2486M–AVR–12/03