attiny25v ATMEL Corporation, attiny25v Datasheet - Page 18

• Manufacturer Part Number: attiny25v
• Description: Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

18
ATtiny25/45/85
The calibrated Oscillator is used to time the EEPROM accesses. Make sure the Oscillator fre-
quency is within the requirements described in
page
The following code examples show one assembly and one C function for erase, write, or atomic
write of the EEPROM. The examples assume that interrupts are controlled (e.g., by disabling
interrupts globally) so that no interrupts will occur during execution of these functions.
Assembly Code Example
C Code Example
EEPROM_write:
void EEPROM_write(unsigned char ucAddress, unsigned char ucData)
{
}
32.
; Wait for completion of previous write
sbic EECR,EEPE
rjmp EEPROM_write
; Set Programming mode
ldi
out
; Set up address (r18:r17) in address register
out EEARH, r18
out EEARL, r17
; Write data (r19) to data register
out EEDR, r19
; Write logical one to EEMPE
sbi EECR,EEMPE
; Start eeprom write by setting EEPE
sbi EECR,EEPE
ret
/* Wait for completion of previous write */
while(EECR & (1<<EEPE))
/* Set Programming mode */
EECR = (0<<EEPM1)|(0<<EEPM0);
/* Set up address and data registers */
EEAR = ucAddress;
EEDR = ucData;
/* Write logical one to EEMPE */
EECR |= (1<<EEMPE);
/* Start eeprom write by setting EEPE */
EECR |= (1<<EEPE);
;
r16, (0<<EEPM1)|(0<<EEPM0)
EECR, r16
“OSCCAL – Oscillator Calibration Register” on
2586K–AVR–01/08