ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 25

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

8.6.4
8.6.5
8.6.6
9223B–AVR–09/11
GPIOR2 – General Purpose I/O Register 2
GPIOR1 – General Purpose I/O Register 1
GPIOR0 – General Purpose I/O Register 0
The next code examples show assembly and C functions for reading the EEPROM. The
examples assume that interrupts are controlled so that no interrupts will occur during execu-
tion of these functions.
Assembly Code Example
C Code Example
Bit
0x2B (0x4B)
Read/Write
Initial Value
Bit
0x2A (0x4A)
Read/Write
Initial Value
Bit
0x1E (0x3E)
Read/Write
Initial Value
Atmel ATmega48PA/88PA/168PA [Preliminary]
EEPROM_read:
unsigned char EEPROM_read(unsigned int uiAddress)
{
}
; Wait for completion of previous write
sbic EECR,EEPE
rjmp EEPROM_read
; Set up address (r18:r17) in address register
out EEARH, r18
out EEARL, r17
; Start eeprom read by writing EERE
sbi EECR,EERE
; Read data from Data Register
in
ret
/* Wait for completion of previous write */
while(EECR & (1<<EEPE))
/* Set up address register */
EEAR = uiAddress;
/* Start eeprom read by writing EERE */
EECR |= (1<<EERE);
/* Return data from Data Register */
return EEDR;
;
r16,EEDR
MSB
MSB
MSB
R/W
R/W
R/W
7
0
7
0
7
0
R/W
R/W
R/W
6
0
6
0
6
0
R/W
R/W
R/W
5
0
5
0
5
0
R/W
R/W
R/W
4
0
4
0
4
0
R/W
R/W
R/W
3
0
3
0
3
0
R/W
R/W
R/W
2
0
2
0
2
0
R/W
R/W
R/W
1
0
1
0
1
0
LSB
LSB
R/W
LSB
R/W
R/W
0
0
0
0
0
0
GPIOR1
GPIOR2
GPIOR0
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