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6 reading the flash, 7 reading the eeprom, 8 programming the fuse low bits – Rainbow Electronics ATmega64C1 User Manual

Page 300: 9 programming the fuse high bits, Figure 24-4

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300

7647A–AVR–02/08

ATmega32/64/M1/C1

Figure 24-4. Programming the EEPROM Waveforms

24.8.6

Reading the Flash

The algorithm for reading the Flash memory is as follows (refer to

“Programming the Flash” on

page 297

for details on Command and Address loading):

1.

A: Load Command “0000 0010”.

2.

G: Load Address High Byte (0x00 - 0xFF).

3.

B: Load Address Low Byte (0x00 - 0xFF).

4.

Set OE to “0”, and BS1 to “0”. The Flash word low byte can now be read at DATA.

5.

Set BS1 to “1”. The Flash word high byte can now be read at DATA.

6.

Set OE to “1”.

24.8.7

Reading the EEPROM

The algorithm for reading the EEPROM memory is as follows (refer to

“Programming the Flash”

on page 297

for details on Command and Address loading):

1.

A: Load Command “0000 0011”.

2.

G: Load Address High Byte (0x00 - 0xFF).

3.

B: Load Address Low Byte (0x00 - 0xFF).

4.

Set OE to “0”, and BS1 to “0”. The EEPROM Data byte can now be read at DATA.

5.

Set OE to “1”.

24.8.8

Programming the Fuse Low Bits

The algorithm for programming the Fuse Low bits is as follows (refer to

“Programming the Flash”

on page 297

for details on Command and Data loading):

1.

A: Load Command “0100 0000”.

2.

C: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.

3.

Give WR a negative pulse and wait for RDY/BSY to go high.

24.8.9

Programming the Fuse High Bits

The algorithm for programming the Fuse High bits is as follows (refer to

“Programming the

Flash” on page 297

for details on Command and Data loading):

RDY/BSY

WR

OE

RESET +12V

PAGEL

BS2

0x11

ADDR. HIGH

DATA

ADDR. LOW

DATA

ADDR. LOW

DATA

XX

XA1

XA0

BS1

XTAL1

XX

A

G

B

C

E

B

C

E

L

K