Datasheet
251
ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
Figure 25-4. Programming the EEPROM Waveforms
25.7.6 Reading the Flash
The algorithm for reading the Flash memory is as follows (refer to Section 25.7.4 “Programming the Flash” on page 248 for
details on command and address loading):
1. A: Load command “0000 0010”.
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 flash word low byte can now be read at DATA.
5. Set BS1 to “1”. The flash word high byte can now be read at DATA.
6. Set OE
to “1”.
25.7.7 Reading the EEPROM
The algorithm for reading the EEPROM memory is as follows (refer to Section 25.7.4 “Programming the Flash” on page 248
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”.
25.7.8 Programming the Fuse Low Bits
The algorithm for programming the fuse low bits is as follows (refer to Section 25.7.4 “Programming the Flash” on page 248
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.
0x11
AG
DATA
XA1
XA0
BS1
BS2
XTAL1
WR
PAGEL
RDY/BSY
OE
RESET +12V
BC
ADDR. LOW ADDR. LOW
B
DATA XX
CE
K
XXDATA
EL
ADDR. HIGH