Datasheet

215
ATmega8A [DATASHEET]
8159E–AVR–02/2013
Table 25-12. Programming the Flash Waveforms
(1)
Note: 1. “XX” is don’t care. The letters refer to the programming description above.
25.7.5 Programming the EEPROM
The EEPROM is organized in pages, see Table 25-6 on page 210. When programming the EEPROM, the program
data is latched into a page buffer. This allows one page of data to be programmed simultaneously. The program-
ming algorithm for the EEPROM Data memory is as follows (refer to “Programming the Flash” on page 213 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 25-2 for signal waveforms).
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
0x10 ADDR. LOW
ADDR. HIGH
DATA
DATA L OW D ATA HI GH ADDR. LOW DATA LOW DATA HIGH
XA1
XA0
BS1
XTAL1
XX XX
XX
AB CDEB C D E G H
F