ATmega325 Atmel Corporation, ATmega325 Datasheet - Page 277

• Manufacturer Part Number: ATmega325
• Manufacturer: Atmel Corporation

Specifications of ATmega325

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

27.6.13
27.6.14
2570N–AVR–05/11
Reading the Signature Bytes
Reading the Calibration Byte
1. A: Load Command “0000 0100”.
2. Set OE to “0”, BS2 to “0” and BS1 to “0”. The status of the Fuse Low bits can now be
3. Set OE to “0”, BS2 to “1” and BS1 to “1”. The status of the Fuse High bits can now be
4. Set OE to “0”, BS2 to “1”, and BS1 to “0”. The status of the Extended Fuse bits can now
5. Set OE to “0”, BS2 to “0” and BS1 to “1”. The status of the Lock bits can now be read at
6. Set OE to “1”.
Figure 27-6. Mapping Between BS1, BS2 and the Fuse and Lock Bits During Read
The algorithm for reading the Signature bytes is as follows (refer to
page 272
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte (0x00 - 0x02).
3. Set OE to “0”, and BS1 to “0”. The selected Signature byte can now be read at DATA.
4. Set OE to “1”.
The algorithm for reading the Calibration byte is as follows (refer to
page 272
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte, 0x00.
3. Set OE to “0”, and BS1 to “1”. The Calibration byte can now be read at DATA.
4. Set OE to “1”.
read at DATA (“0” means programmed).
read at DATA (“0” means programmed).
be read at DATA (“0” means programmed).
DATA (“0” means programmed).
for details on Command and Address loading):
for details on Command and Address loading):
Extended Fuse Byte
Fuse Low Byte
Fuse High Byte
Lock Bits
BS2
BS2
0
1
0
1
ATmega325/3250/645/6450
BS1
0
1
“Programming the Flash” on
“Programming the Flash” on
DATA
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