Rainbow Electronics ATmega8515L - Manual (Page 184)

184
ATmega8515(L)
2512A–AVR–04/02
Figure 77. Programming the EEPROM Waveforms
Reading the Flash The algorithm for reading the Flash memory is as follows (refer to “Programming the
Flash” on page 181 for details on Command and Address loading):
1. A: Load Command “0000 0010”.
2. G: Load Address High Byte ($00 - $FF).
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 BS1 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 181 for details on Command and Address loading):
1. A: Load Command “0000 0011”.
2. G: Load Address High Byte ($00 - $FF).
3. B: Load Address Low Byte ($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”.
Programming the Fuse Low
Bits The algorithm for programming the Fuse Low bits is as follows (refer to “Programming
the Flash” on page 181 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. Set BS1 to “0” and BS2 to “0”. This selects low data byte.
4. Give WR a negative pulse and wait for RDY/BSY to go high.
Programming the Fuse High
Bits The algorithm for programming the Fuse High bits is as follows (refer to “Programming
the Flash” on page 181 for details on Command and Data loading):
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
$10 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