atmega3250v-8auatmega325v-8ai ATMEL Corporation, atmega3250v-8auatmega325v-8ai Datasheet - Page 273

• Manufacturer Part Number: atmega3250v-8auatmega325v-8ai
• Description: Atmega3250 8-bit Microcontroller With In-system Programmable Flash
• Manufacturer: ATMEL Corporation

27.6.5
2570L–AVR–08/07
Programming the EEPROM
Figure 27-3. Programming the Flash Waveforms
Note:
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
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
3. Wait until to RDY/BSY goes high before programming the next page (See
goes low.
signal waveforms).
RESET +12V
RDY/BSY
PAGEL
XTAL1
1. “XX” is don’t care. The letters refer to the programming description above.
DATA
XA1
XA0
BS1
BS2
WR
OE
0x10
“Programming the Flash” on page 271
A
ADDR. LOW
B
DATA LOW
C
DATA HIGH
D
XX
E
ADDR. LOW
Table 27-11 on page
B
ATmega325/3250/645/6450
DATA LOW
(1)
C
F
DATA HIGH
D
for details on Command, Address and
XX
E
ADDR. HIGH
269. When programming the
G
H
XX
Figure 27-4
for
273