Datasheet

343
2549O–AVR–05/12
ATmega640/1280/1281/2560/2561
K. End Page Programming
1. 1. Set XA1, XA0 to “10”. This enables command loading.
2. Set DATA to “0000 0000”. This is the command for No Operation.
3. Give XTAL1 a positive pulse. This loads the command, and the internal write signals are
reset.
Figure 30-2. Addressing the Flash Which is Organized in Pages
(1)
Note: 1. PCPAGE and PCWORD are listed in Table 30-7 on page 338.
Figure 30-3. Programming the Flash Waveforms
(1)
Note: 1. “XX” is don’t care. The letters refer to the programming description above.
30.7.5 Programming the EEPROM
The EEPROM is organized in pages, see Table 30-8 on page 338. 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
PROGRAM MEMORY
WORD ADDRESS
WITHIN A PAGE
PAGE ADDRESS
WITHIN THE FLASH
INSTRUCTION WORD
PAG E
PCWORD[PAGEMSB:0]:
00
01
02
PAGEEND
PAG E
PCWORDPCPAGE
PCMSB
PAGEMSB
PROGRAM
COUNTER
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
ABCDEBC DEG
F
ADDR. EXT.H
H
I