Rainbow Electronics ATmega163L - Manual (Page 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 LOW DATA
XA1
XA2
BS1
XTAL1
RDY/BSY
RESET
WR
OE
+12V
BS2
PAGEL