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ATMEGA6450_14 Datasheet, PDF (277/362 Pages) ATMEL Corporation – High Endurance Non-volatile Memory Segments | |||
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ATmega325/3250/645/6450
1. A: Load Command â0000 0100â.
2. Set OE to â0â, BS2 to â0â and BS1 to â0â. The status of the Fuse Low bits can now be
read at DATA (â0â means programmed).
3. Set OE to â0â, BS2 to â1â and BS1 to â1â. The status of the Fuse High bits can now be
read at DATA (â0â means programmed).
4. Set OE to â0â, BS2 to â1â, and BS1 to â0â. The status of the Extended Fuse bits can now
be read at DATA (â0â means programmed).
5. Set OE to â0â, BS2 to â0â and BS1 to â1â. The status of the Lock bits can now be read at
DATA (â0â means programmed).
6. Set OE to â1â.
Figure 27-6. Mapping Between BS1, BS2 and the Fuse and Lock Bits During Read
Fuse Low Byte
0
Extended Fuse Byte
1
BS2
Lock Bits
0
0
DATA
1
BS1
Fuse High Byte
1
BS2
27.6.13
Reading the Signature Bytes
The algorithm for reading the Signature bytes is as follows (refer to âProgramming the Flashâ on
page 272 for details on Command and Address loading):
1. A: Load Command â0000 1000â.
2. B: Load Address Low Byte (0x00 - 0x02).
3. Set OE to â0â, and BS1 to â0â. The selected Signature byte can now be read at DATA.
4. Set OE to â1â.
27.6.14
Reading the Calibration Byte
The algorithm for reading the Calibration byte is as follows (refer to âProgramming the Flashâ on
page 272 for details on Command and Address loading):
1. A: Load Command â0000 1000â.
2. B: Load Address Low Byte, 0x00.
3. Set OE to â0â, and BS1 to â1â. The Calibration byte can now be read at DATA.
4. Set OE to â1â.
2570NâAVRâ05/11
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