at90pwm81-16se ATMEL Corporation, at90pwm81-16se Datasheet - Page 24

• Manufacturer Part Number: at90pwm81-16se
• Description: 8-bit Avr Microcontroller With 8k Bytes In- System Programmable Flash
• Manufacturer: ATMEL Corporation

5.4.1
24
AT90PWM81
Code examples
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 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 software. If such code is present, the EEPROM write function must also wait for any ongo-
ing 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);
;
7734M–AVR–03/10