ATMEGA169 ATMEL [ATMEL Corporation], ATMEGA169 Datasheet - Page 278

• Manufacturer Part Number: ATMEGA169
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Reading the Fuse and Lock
Bits
Reading the Signature Bytes
Reading the Calibration Byte
278
ATmega169/V
The algorithm for reading the Fuse and Lock bits is as follows (refer to “Programming
the Flash” on page 273 for details on Command loading):
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
3. Set OE to “0”, BS2 to “1” and BS1 to “1”. The status of the Fuse High bits can
4. Set OE to “0”, BS2 to “1”, and BS1 to “0”. The status of the Extended Fuse bits
5. Set OE to “0”, BS2 to “0” and BS1 to “1”. The status of the Lock bits can now be
6. Set OE to “1”.
Figure 124. Mapping Between BS1, BS2 and the Fuse and Lock Bits During Read
The algorithm for reading the Signature bytes is as follows (refer to “Programming the
Flash” on page 273 for details on Command and Address loading):
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte (0x00 - 0x02).
3. Set OE to “0”, and BS to “0”. The selected Signature byte can now be read at
4. Set OE to “1”.
The algorithm for reading the Calibration byte is as follows (refer to “Programming the
Flash” on page 273 for details on Command and Address loading):
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”.
now be read at DATA (“0” means programmed).
now be read at DATA (“0” means programmed).
can now be read at DATA (“0” means programmed).
read at DATA (“0” means programmed).
DATA.
Fuse Low Byte
Extended Fuse Byte
Fuse High Byte
Lock Bits
BS2
BS2
0
1
0
1
BS1
0
1
DATA
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