Rainbow Electronics ATmega3290P_V - Manual (Page 290)

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ATmega329/3290/649/6490
2552H–AVR–11/06
Figure 122. Programming the Flash Waveforms (1)
Note: 1. “XX” is don’t care. The letters refer to the programming description above.
Programming the EEPROM The EEPROM is organized in pages, see Table 133 on page 286. 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 288 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
123 for signal waveforms).
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
0x10 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