AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 334

• Manufacturer Part Number: AT90CAN128-16AE
• Description: 8-bit Avr Microcontroller With 128K Bytes of Isp Flash And CAN Controller.flash (Kbytes) 128 Vcc (V) 2.7-5.5 EEPROM (Kbytes) 4 SRAM (bytes) 4K CAN (mess. Obj.) 15
• Manufacturer: ATMEL Corporation

Programming the Lock Bits
Reading the Fuse and
Lock Bits
Reading the Signature Bytes
Reading the Calibration Byte
334
AT90CAN128
The algorithm for programming the Lock bits is as follows (refer to “Programming the
Flash” on page 329 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 329 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 fo 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 158. 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 329 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 DATA.
4. Set OE to “1”.
The algorithm for reading the Calibration byte is as follows (refer to “Programming the
Flash” on page 329 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”.
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).
Extended Fuse Byte
Fuse High Byte
Fuse Low Byte
Lock Bits
BS2
BS2
0
1
0
1
BS1
0
1
DATA
4250C–CAN–03/04