ATMEGA32 Datasheet, PDF (264/317 Pages) ATMEL Corporation – 8-bit AVR Microcontroller with 32K Bytes In-System Programmable Flash

Reading the EEPROM
Programming the Fuse Low
Bits
Programming the Fuse High
Bits
6. Set OE to “1”.
The algorithm for reading the EEPROM memory is as follows (refer to “Programming the
Flash” on page 260 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”.
The algorithm for programming the Fuse Low bits is as follows (refer to “Programming
the Flash” on page 260 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 “0” and BS2 to “0”.
4. 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 260 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” and BS2 to “0”. 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.
Figure 131. Programming the Fuses
Write Fuse Low byte
DATA
A
C
$40
DATA
XX
Write Fuse high byte
A
C
$40
DATA
XX
XA1
XA0
BS1
BS2
XTAL1
WR
RDY/BSY
RESET +12V
OE
PAGEL
264 ATmega32(L)
2503F–AVR–12/03