Rainbow Electronics ATtiny2313 - Manual (Page 19)

19
ATtiny2313
2543A–AVR–08/03
The following code examples show one assembly and one C function for writing to the
EEPROM. The examples assume that interrupts are controlled (e.g. by disabling inter-
rupts globally) so that no interrupts will occur during execution of these functions.
Assembly Code Example
EEPROM_write:
; Wait for completion of previous write
sbic EECR,EEWE
rjmp EEPROM_write
; Set up address (r17) in address register
out EEAR, 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
C Code Example
void EEPROM_write(unsigned int uiAddress, unsigned char ucData)
{
/* Wait for completion of previous write */
while(EECR & (1<
;
/* Set up address and data registers */
EEAR = uiAddress;
EEDR = ucData;
/* Write logical one to EEMWE */
EECR |= (1<
/* Start eeprom write by setting EEWE */
EECR |= (1<
}