ATMEGA325A-MU Atmel, ATMEGA325A-MU Datasheet - Page 294

• 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

26.7.7
26.7.8
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ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/645
Reading the EEPROM
Programming the Fuse Low Bits
Programming the Fuse High Bits
Programming the Extended Fuse Bits
The algorithm for reading the EEPROM memory is as follows (refer to
on page 289
1. A: Load Command “0000 0011”.
2. G: Load Address High Byte (0x00 - 0xFF).
3. B: Load Address Low Byte (0x00 - 0xFF).
4. Set OE to “0”, and BS1 to “0”. The EEPROM Data byte can now be read at DATA.
5. Set OE to “1”.
The algorithm for programming the Fuse Low bits is as follows (refer to
on page 289
1. A: Load Command “0100 0000”.
2. C: Load Data Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3. Give WR a negative pulse and wait for RDY/BSY to go high.
The algorithm for programming the Fuse High bits is as follows (refer to
Flash” on page 289
1. A: Load Command “0100 0000”.
2. C: Load Data Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3. Set BS1 to “1” and BS2 to “0”. This selects high fuse byte.
4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. Set BS1 to “0”. This selects low data byte.
The algorithm for programming the Extended Fuse bits is as follows (refer to
Flash” on page 289
1. 1. A: Load Command “0100 0000”.
2. 2. C: Load Data Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3. 3. Set BS1 to “0” and BS2 to “1”. This selects extended fuse byte.
4. 4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. 5. Set BS2 to “0”. This selects low data byte.
for details on Command and Address loading):
for details on Command and Data loading):
for details on Command and Data loading):
for details on Command and Data loading):
”Programming the Flash”
”Programming the Flash”
”Programming the
”Programming the
8285B–AVR–03/11