Programming The Eeprom; Programming The Flash Waveforms - Atmel ATmega128 Manual

Programming the
EEPROM
2467S–AVR–07/09
Figure 137. Programming the Flash Waveforms
A
0x10 ADDR. LOW
DATA
XA1
XA0
BS1
XTAL1
WR
RDY/BSY
RESET +12V
OE
PAGEL
BS2
Note: "XX" is don't care. The letters refer to the programming description above.
The EEPROM is organized in pages, see
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 293
Data loading):
1. A: Load Command "0001 0001".
2. G: Load Address High Byte ($00 - $FF).
3. B: Load Address Low Byte ($00 - $FF).
4. C: Load Data ($00 - $FF).
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 138 for signal waveforms.)
B C D E B
DATA LOW DATA HIGH ADDR. LOW DATA LOW
XX
Table 124 on page
ATmega128
F
C D E G H
DATA HIGH ADDR. HIGH XX
XX
292. When programming the
for details on Command, Address and
295