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Rainbow Electronics ATmega64C1 User Manual

Page 298

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298

7647A–AVR–02/08

ATmega32/64/M1/C1

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

1.

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

2.

Set BS1 to “1”. This selects high address.

3.

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

4.

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

H. Program Page

1.

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

2.

Wait until RDY/BSY goes high (See

Figure 24-3

for signal waveforms).

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

J. 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 24-2. Addressing the Flash Which is Organized in Pages

(1)

Note:

1. PCPAGE and PCWORD are listed in

Table 24-12 on page 295

.

PROGRAM MEMORY

WORD ADDRESS
WITHIN A PAGE

PAGE ADDRESS
WITHIN THE FLASH

INSTRUCTION WORD

PAGE

PCWORD[PAGEMSB:0]:

00

01

02

PAGEEND

PAGE

PCWORD

PCPAGE

PCMSB

PAGEMSB

PROGRAM
COUNTER