Datasheet

Table Of Contents
1. Step A: Load Command “0100 0000”.
2. Step 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.
Figure 29-5. 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
BS2
29.7.10. Programming the Lock Bits
The algorithm for programming the Lock bits is as follows (Please refer to Programming the Flash for
details on Command and Data loading):
1. Step A: Load Command “0010 0000”.
2. Step C: Load Data Low Byte. Bit n = “0” programs the Lock bit.
3. Give WR a negative pulse and wait for RDY/BSY to go high.
The Lock bits can only be cleared by executing Chip Erase.
29.7.11. Reading the Fuse and Lock Bits
The algorithm for reading the Fuse and Lock bits is as follows (Please refer to Programming the Flash for
details on Command loading):
1. Step A: Load Command “0000 0100”.
2. Set OE to “0”, BS2 to “0”, and BS1 to “0”. The status of the Fuse Low bits can now be read at DATA
(“0” means programmed).
3. Set OE to “0”, BS2 to “1”, and BS1 to “1”. The status of the Fuse High bits can now be read at
DATA (“0” means programmed).
Atmel ATmega32A [DATASHEET]
Atmel-8155I-ATmega32A_Datasheet_Complete-08/2016
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