Rainbow Electronics ATmega128L - Manual (Page 287)

287
ATmega128(L)
2467B–09/01
Figure 137. Programming the Flash Waveforms
Note: “XX” is don’t care. The letters refer to the programming description above.
Programming the EEPROM The EEPROM is organized in pages, see Table 125 on page 284. 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 285 for details on
Command, Address and 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)
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
$10 ADDR. LOW ADDR. HIGH
DATA
DATA LOW DATA HIGH ADDR. LOW DATA LOW DATA HIGH
XA1
XA0
BS1
XTAL1
XX XX XX
A B C D E B C D E G H
F