Datasheet

303
8011O–AVR–07/10
ATmega164P/324P/644P
Figure 24-4. Programming the EEPROM Waveforms
24.7.6 Reading the Flash
The algorithm for reading the Flash memory is as follows (refer to ”Programming the Flash” on
page 300 for details on Command and Address loading):
1. A: Load Command “0000 0010”.
2. H: Load Address Extended Byte (0x00- 0xFF).
3. G: Load Address High Byte (0x00 - 0xFF).
4. B: Load Address Low Byte (0x00 - 0xFF).
5. Set OE
to “0”, and BS1 to “0”. The Flash word low byte can now be read at DATA.
6. Set BS to “1”. The Flash word high byte can now be read at DATA.
7. Set OE
to “1”.
24.7.7 Reading the EEPROM
The algorithm for reading the EEPROM memory is as follows (refer to ”Programming the Flash”
on page 300 for details on Command and Address loading):
1. A: Load Command “0000 0011”.
2. G: Load Address High Byte (0x00 - 0xFF).
3. B: Load Address Low Byte (0x00 - 0xFF).
4. Set OE
to “0”, and BS1 to “0”. The EEPROM Data byte can now be read at DATA.
5. Set OE
to “1”.
24.7.8 Programming the Fuse Low Bits
The algorithm for programming the Fuse Low bits is as follows (refer to ”Programming the Flash”
on page 300 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.
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
0x11 ADDR. HIGH
DATA
ADDR. LOW DATA ADDR. LOW DATA XX
XA1
XA0
BS1
XTAL1
XX
AGBCEB C EL
K