ATMEGA325A-MU Atmel, ATMEGA325A-MU Datasheet - Page 26

• Manufacturer Part Number: ATMEGA325A-MU
• Description: IC MCU AVR 32K FLASH 64VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA325A-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.6
7.6.1
7.6.2
7.6.3
26
Register Description
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/645
EEARH and EEARL – EEPROM Address Register ATmega165A/ATmega165PA
EEARH and EEARL – EEPROM Address
RegisterATmega325A/325PA/3250A/3250PA/625A/645P/6450A/6450P
EEDR – EEPROM Data Register
• Bits 15:9 – Reserved
These bits are reserved and will always read as zero.
• Bits 8:0 – EEAR8:0: EEPROM Address
The EEPROM Address Registers – EEARH and EEARL specify the EEPROM address in the
512 bytes EEPROM space. The EEPROM data bytes are addressed linearly between 0 and
511. The initial value of EEAR is undefined. A proper value must be written before the EEPROM
may be accessed.
• Bits 15:11 – Reserved
These bits are reserved bits in the
ATmega325A/325PA/3250A/3250PA/645A/645P/6450A/6450P and will always read as zero.
• Bits 10:0 – EEAR10:0: EEPROM Address
The EEPROM Address Registers – EEARH and EEARL specify the EEPROM address in the
1/2K bytes EEPROM space. The EEPROM data bytes are addressed linearly between 0 and
1023/2047. The initial value of EEAR is undefined. A proper value must be written before the
EEPROM may be accessed.
Note:
Bit
0x22 (0x42)
0x21 (0x41)
Read/Write
Initial Value
Bit
0x22 (0x42)
0x21 (0x41)
Read/Write
Initial Value
Bit
0x20 (0x40)
Read/Write
Initial Value
1. EEAR10 is only valid for ATmega645A/ATmega645P/ATmega6450A/ATmega6450P
EEAR7
R/W
15
R
X
–
7
0
EEAR7
MSB
R/W
R/W
15
R
X
–
7
0
7
0
EEAR6
R/W
14
R
–
6
0
X
EEAR6
R/W
R/W
14
R
X
–
6
0
6
0
EEAR5
R/W
13
R
X
–
5
0
EEAR5
R/W
R/W
13
R
X
–
5
0
5
0
EEAR4
R/W
12
R
X
–
4
0
EEAR4
R/W
R/W
12
R
X
–
4
0
4
0
EEAR3
R/W
11
R
–
3
0
X
EEAR3
R/W
R/W
11
–
3
R
0
X
3
0
EEAR10
EEAR2
R/W
R/W
10
X
X
2
EEAR2
R/W
R/W
(1)
10
–
2
R
0
X
2
0
EEAR9
EEAR1
R/W
R/W
X
X
9
1
EEAR1
R/W
R/W
R
9
–
1
0
X
1
0
EEAR8
EEAR0
R/W
R/W
EEAR8
EEAR0
8
0
X
X
LSB
R/W
R/W
R/W
8
0
X
X
0
0
8285B–AVR–03/11
EEARH
EEARL
EEARH
EEARL
EEDR