Datasheet

258
7734Q–AVR–02/12
AT90PWM81/161
L: Program EEPROM page
1. Set BS1 to “0”.
2. Give WR
a negative pulse. This starts programming of the EEPROM page. RDY/BSY
goes low.
3. Wait until to RDY/BSY
goes high before programming the next page (see Figure 21-4
for signal waveforms).
Figure 21-4. Programming the EEPROM waveforms.
21.7.6 Reading the Flash
The algorithm for reading the Flash memory is as follows (refer to “Programming the Flash” on
page 255 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”.
21.7.7 Reading the EEPROM
The algorithm for reading the EEPROM memory is as follows (refer to “Programming the Flash”
on page 255 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”.
21.7.8 Programming the Fuse Low Bits
The algorithm for programming the Fuse Low bits is as follows (refer to “Programming the Flash”
on page 255 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.
RDY/BSY
WR
OE
RESET +12V
0x11 ADDR. HIGH
DATA
ADDR. L OW DATA ADDR. LOW DATA XX
XA1/BS2
XA0
PAGEL/BS1
XTAL1
XX
AGBCEB C EL
K