ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 352

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Programming the Fuse Low
Bits
Programming the Fuse High
Bits
Programming the Extended
Fuse Bits
352
ATmega640/1280/1281/2560/2561
4. Set OE to “0”, and BS1 to “0”. The EEPROM Data byte can now be read at
5. Set OE to “1”.
The algorithm for programming the Fuse Low bits is as follows (refer to “Programming
the Flash” on page 348 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.
The algorithm for programming the Fuse High bits is as follows (refer to “Programming
the Flash” on page 348 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 BS2, BS1 to “01”. This selects high data byte.
4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. Set BS2, BS1 to “00”. This selects low data byte.
The algorithm for programming the Extended Fuse bits is as follows (refer to “Program-
ming the Flash” on page 348 for details on Command and Data loading):
1. 1. A: Load Command “0100 0000”.
2. 2. C: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse
3. 3. Set BS2, BS1 to “10”. This selects extended data byte.
4. 4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. 5. Set BS2, BS1 to “00”. This selects low data byte.
Figure 142. Programming the FUSES Waveforms
RESET +12V
RDY/BSY
DATA.
bit.
PAGEL
XTAL1
DATA
BS2
XA1
XA0
BS1
WR
OE
0x40
A
DATA
C
Write Fuse Low byte
XX
0x40
A
DATA
C
Write Fuse high byte
XX
0x40
A
DATA
C
Write Extended Fuse byte
XX
2549K–AVR–01/07