Rainbow Electronics ATmega64L - Manual (Page 262)

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ATmega16(L)
2466B–09/01
5. Set BS1 to "1". The Flash word high byte can now be read at DATA.
6. Set OE to "1".
Reading the EEPROM The algorithm for reading the EEPROM memory is as follows (refer to “Programming the
Flash” on page 258 for details on Command and Address loading):
1. A: Load Command "0000 0011".
2. G: Load Address High Byte ($00 - $FF)
3. B: Load Address Low Byte ($00 - $FF)
4. Set OE to "0", and BS1 to "0". The EEPROM Data byte can now be read at
DATA.
5. Set OE to "1".
Programming the Fuse Low
Bits The algorithm for programming the Fuse Low bits is as follows (refer to “Programming
the Flash” on page 258 for details on Command and Data loading):
1. A: Load Command "0100 0000".
2. C: Load Data Low Byte. Bit n = "0" programs and bit n = "1" erases the Fuse bit.
3. Give WR a negative pulse and wait for RDY/BSY to go high.
Programming the Fuse High
Bits The algorithm for programming the Fuse high bits is as follows (refer to “Programming
the Flash” on page 258 for details on Command and Data loading):
1. A: Load Command "0100 0000".
2. C: Load Data Low Byte. Bit n = "0" programs and bit n = "1" erases the Fuse bit.
3. Set BS1 to '1'. This selects high data byte.
4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. Set BS1 to '0'. This selects low data byte.
Programming the Lock Bits The algorithm for programming the Lock bits is as follows (refer to “Programming the
Flash” on page 258 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.
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.
Reading the Fuse and Lock
Bits The algorithm for reading the Fuse and Lock bits is as follows (refer to “Programming
the Flash” on page 258 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
now be read at DATA ("0" means programmed).
3. Set OE to "0", BS2 to "1" and BS1 to "1". The status of the Fuse High bits can
now be read at DATA ("0" means programmed).
4. Set OE to "0", BS2 to "0" and BS1 to "1". The status of the Lock bits can now be
read at DATA ("0" means programmed).
5. Set OE to "1".