ATTIny2313-16MI ATMEL Corporation, ATTIny2313-16MI Datasheet - Page 169

• Manufacturer Part Number: ATTIny2313-16MI
• Description: 8-bit AVR Microcontroller with 2K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Programming the Lock Bits
Reading the Fuse and Lock
Bits
Reading the Signature Bytes
2543C–AVR–12/03
The algorithm for programming the Lock bits is as follows (refer to “Programming the
Flash” on page 165 for details on Command and Data loading):
1. A: Load Command “0010 0000”.
2. C: Load Data Low Byte. Bit n = “0” programs the Lock bit. If LB mode 3 is pro-
3. Give WR a negative pulse and wait for RDY/BSY to go high.
The Lock bits can only be cleared by executing Chip Erase.
The algorithm for reading the Fuse and Lock bits is as follows (refer to “Programming
the Flash” on page 165 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 73. 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 165 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”.
grammed (LB1 and LB2 is programmed), it is not possible to program the Boot
Lock bits by any External Programming mode.
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
ATtiny2313/V
DATA
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