at90ls4433 ATMEL Corporation, at90ls4433 Datasheet - Page 91

• Manufacturer Part Number: at90ls4433
• Description: At90s4433 8-bit Avr Microcontroller With 4k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Programming the Fuse Bits
Programming the Lock Bits
Reading the Fuse and Lock
Bits
1042H–AVR–04/03
The algorithm for programming the Fuse bits is as follows (refer to “Programming the
Flash” for details on command and data loading):
A: Load Command “0100 0000”.
B: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
1. Give WR a t
The algorithm for programming the Lock bits is as follows (refer to “Programming the
Flash” for details on command and data loading):
A: Load Command “0010 0000”.
B: Load Data Low Byte. Bit n = “0” programs the Lock bit.
C: Write Data Low Byte.
The Lock bits can only be cleared by executing Chip Erase.
The algorithm for reading the Fuse and Lock bits is as follows (refer to “Programming
the Flash” for details on command loading):
A: Load Command “0000 0100”.
1. Set OE to “0”, and BS to “0”. The status of the Fuse bits can now be read at
2. Set BS to “1”. The status of the Lock bits can now be read at DATA (“0” means
3. Set OE to “1”.
Bit 5 = SPIEN Fuse bit
Bit 4 = BODLEVEL Fuse bit
Bit 3 = BODEN Fuse bit
Bit 2 = CKSEL2 Fuse bit
Bit 1 = CKSEL1 Fuse bit
Bit 0 = CKSEL0 Fuse bit
Bits 7 - 6 = “1”. These bits are reserved and should be left unprogrammed (“1”).
is found in Table 33. Programming the Fuse bits does not generate any activity
on the RDY/BSY pin.
Bit 2 = Lock bit 2
Bit 1 = Lock bit 1
Bits 7 - 3, 0 = “1”. These bits are reserved and should be left unprogrammed (“1”).
DATA (“0” means programmed).
Bit 5 = SPIEN Fuse bit
Bit 4 = BODLEVEL Fuse bit
Bit 3 = BODEN Fuse bit
Bit 2 = CKSEL2 Fuse bit
Bit 1 = CKSEL1 Fuse bit
Bit 0 = CKSEL0 Fuse bit
programmed).
Bit 2 = Lock Bit 2
Bit 1= Lock Bit 1
WLWH_PFB
wide negative pulse to execute the programming, t
AT90S/LS4433
WLWH_PFB
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