ATMEGA640 datasheet(332/436 Pages) MICROCHIP

332 / 436 page

332

ATmega640/V-1280/V-1281/V-2560/V-2561/V [DATASHEET]

DS40002211A

D. Load Data High Byte

1. Set BS1 to “1”. This selects high data byte.

2. Set XA1, XA0 to “01”. This enables data loading.

3. Set DATA = Data high byte (0x00 - 0xFF).

4. Give XTAL1 a positive pulse. This loads the data byte.

E. Latch Data

1. Set BS1 to “1”. This selects high data byte.

2. Give PAGEL a positive pulse. This latches the data bytes. See Figure 30-3 on page 333 for signal

waveforms.

F. Repeat B through E until the entire buffer is filled or until all data within the page is loaded

While the lower bits in the address are mapped to words within the page, the higher bits address the pages within

the FLASH. This is illustrated in Figure 30-2 on page 333. Note that if less than eight bits are required to address

words in the page (pagesize < 256), the most significant bit(s) in the address low byte are used to address the

page when performing a Page Write.

G. Load Address High byte (Address bits15:8)

1. Set XA1, XA0 to “00”. This enables address loading.

2. Set BS2, BS1 to “01”. This selects the address high byte.

3. Set DATA = Address high byte (0x00 - 0xFF).

4. Give XTAL1 a positive pulse. This loads the address high byte.

H. Load Address Extended High byte (Address bits 23:16)

1. Set XA1, XA0 to “00”. This enables address loading.

2. Set BS2, BS1 to “10”. This selects the address extended high byte.

3. Set DATA = Address extended high byte (0x00 - 0xFF).

4. Give XTAL1 a positive pulse. This loads the address high byte.

I. Program Page

1. Set BS2, BS1 to “00”.

2. Give WR a negative pulse. This starts programming of the entire page of data. RDY/BSY goes low.

3. Wait until RDY/BSY goes high (see Figure 30-3 on page 333 for signal waveforms).

J. Repeat B through I until the entire Flash is programmed or until all data has been programmed

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.

ATMEGA640 Datasheet(PDF) 332 Page - Microchip Technology