Rainbow-electronics ATmega163L Manual de usuario descargar pdf (Pagina 129)

ATmega163(L)

129

3. Wait until to RDY/BSY

goes high before programming the next byte.

(See Figure 84 for signal waveforms)

The loaded command and address are retained in the device during programming. For efficient programming, the following

should be considered.

• The command needs only be loaded once when writing or reading multiple memory locations.

• Address high byte needs only be loaded before programming a new 256 word page in the EEPROM.

• Skip writing the data value $FF, that is the contents of the entire EEPROM after a Chip Erase.

These considerations also applies to Flash, EEPROM and Signature bytes reading.

Figure 84. Programming the EEPROM Waveforms

Reading the Flash

The algorithm for reading the Flash memory is as follows (refer to “Programming the Flash” on page 126 for details on

Command and Address loading):

1. A: Load Command ‘0000 0010’.

2. H: Load Address High Byte ($00-$0F/$1F)

3. B: Load Address Low Byte ($00 - $FF)

4. Set OE

to ‘0’, and BS1 to ‘0’. The Flash word low byte can now be read at DATA.

5. Set BS to ‘1’. The Flash word high byte can now be read at DATA.

6. Set OE to ‘1’.

Reading the EEPROM

The algorithm for reading the EEPROM memory is as follows (refer to “Programming the Flash” on page 126 for details on

Command and Address loading):

1. A: Load Command ‘0000 0011’.

2. H: Load Address High Byte ($00-$01)

3. B: Load Address ($00 - $FF)

4. Set OE

to ‘0’, and BS1 to ‘0’. The EEPROM Data byte can now be read at DATA.

5. Set OE to ‘1’.

$11 ADDR. HIGH ADDR. LOW DATA LOWDATA

XA1

XA2

BS1

XTAL1

RDY/BSY

RESET

+12V

BS2

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Rainbow-electronics ATmega163L Manual de usuario Pagina 129