9 programming the fuse high bits, 10 programming the extended fuse bits – Rainbow Electronics ATtiny861_V User Manual
Page 178
178
2588B–AVR–11/06
ATtiny261/461/861
22.7.9
Programming the Fuse High Bits
The algorithm for programming the Fuse High bits is as follows (refer to
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 “1” and BS2 to “0”. This selects high data byte.
4.
Give WR a negative pulse and wait for RDY/BSY to go high.
5.
Set BS1 to “0”. This selects low data byte.
22.7.10
Programming the Extended Fuse Bits
The algorithm for programming the Extended Fuse bits is as follows (refer to
for details on Command and Data loading):
1.
1. A: Load Command “0100 0000”.
2.
2. C: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3.
3. Set BS1 to “0” and BS2 to “1”. This selects extended data byte.
4.
4. Give WR a negative pulse and wait for RDY/BSY to go high.
5.
5. Set BS2 to “0”. This selects low data byte.
Figure 22-5. Programming the FUSES Waveforms
RDY/BSY
WR
OE
RESET +12V
0x40
DATA
DATA
XX
XA1/BS2
XA0
PAGEL/BS1
XTAL1
A
C
0x40
DATA
XX
A
C
Write Fuse Low byte
Write Fuse high byte
0x40
DATA
XX
A
C
Write Extended Fuse byte