ATMEGA8_08 Datasheet, PDF (231/308 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

Programming the
EEPROM
ATmega8(L)
Figure 106. Programming the Flash Waveforms⁽¹⁾
F
DATA
XA1
XA0
BS1
XTAL1
WR
RDY/BSY
RESET +12V
OE
PAGEL
BS2
AB
C D EB
C
D
E
G
H
0x10 ADDR. LOW DATA LOW DATA HIGH
XX ADDR. LOW DATA LOW DATA HIGH
XX
ADDR. HIGH
XX
Note: 1. “XX” is don’t care. The letters refer to the programming description above.
The EEPROM is organized in pages, see Table 90 on page 225. When programming the
EEPROM, the program data is latched into a page buffer. This allows one page of data to be
programmed simultaneously. The programming algorithm for the EEPROM Data memory is as
follows (refer to “Programming the Flash” on page 229 for details on Command, Address and
Data loading):
1. A: Load Command “0001 0001”.
2. G: Load Address High byte (0x00 - 0xFF).
3. B: Load Address Low byte (0x00 - 0xFF).
4. C: Load Data (0x00 - 0xFF).
5. E: Latch data (give PAGEL a positive pulse).
K: Repeat 3 through 5 until the entire buffer is filled.
L: Program EEPROM page.
1. Set BS1 to “0”.
2. Give WR a negative pulse. This starts programming of the EEPROM page. RDY/BSY
goes low.
3. Wait until to RDY/BSY goes high before programming the next page.
(See Figure 107 for signal waveforms).
2486T–AVR–05/08
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