Rainbow Electronics ATmega162V - Manual (Page 240)

240
ATmega162/V
2513E–AVR–09/03
Programming the Fuse High
Bits The algorithm for programming the Fuse high bits is as follows (refer to “Programming
the Flash” on page 236 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.
Programming the Extended
Fuse Bits The algorithm for programming the Extended Fuse bits is as follows (refer to “Program-
ming the Flash” on page 236 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 100. Programming the FUSES Waveforms
RDY/BSY
WR
OE
RESET +12V
PAGEL
0x40
DATA
DATA XX
XA1
XA0
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
BS2