ATMEGA644PV ATMEL [ATMEL Corporation], ATMEGA644PV Datasheet - Page 302

• Manufacturer Part Number: ATMEGA644PV
• Description: 8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

25.7.9
25.7.10
25.7.11
302
ATmega164P/324P/644P
Programming the Fuse High Bits
Programming the Extended Fuse Bits
Programming the Lock Bits
The algorithm for programming the Fuse High bits is as follows (refer to
Flash” on page 298
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
Flash” on page 298
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 bit.
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 25-5. Programming the FUSES Waveforms
The algorithm for programming the Lock bits is as follows (refer to
page 298
1. A: Load Command “0010 0000”.
2. C: Load Data Low Byte. Bit n = “0” programs the Lock bit. If LB mode 3 is programmed
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.
(LB1 and LB2 is programmed), it is not possible to program the Boot Lock bits by any
External Programming mode.
RESET +12V
RDY/BSY
PAGEL
XTAL1
DATA
for details on Command and Data loading):
XA1
XA0
BS1
BS2
WR
OE
0x40
A
for details on Command and Data loading):
for details on Command and Data loading):
DATA
C
Write Fuse Low byte
XX
0x40
A
DATA
C
Write Fuse high byte
XX
”Programming the Flash” on
0x40
A
DATA
C
Write Extended Fuse byte
”Programming the
”Programming the
XX
8011D–AVR–02/07