at90ls8535-8mi ATMEL Corporation, at90ls8535-8mi Datasheet - Page 98

• Manufacturer Part Number: at90ls8535-8mi
• Description: 8-bit Microcontroller With 8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Programming the Fuse Bits
Programming the Lock Bits
Reading the Fuse and Lock
Bits
Reading the Signature Bytes
98
AT90S/LS8535
The algorithm for programming the Fuse bits is as follows (refer to “Programming the
Flash” for details on command and data loading):
1. A: Load Command “0100 0000”.
2. D: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3. Give WR a
The algorithm for programming the Lock bits is as follows (refer to “Programming the
Flash” on page 95 for details on command and data loading):
1. A: Load Command “0010 0000”.
2. D: Load Data Low Byte. Bit n = “0” programs the Lock bit.
3. E: 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” on page 95 for details on command loading):
1. A: Load Command “0000 0100”.
2. Set OE to “0” and BS to “1”. The status of the Fuse and Lock bits can now be
3. Set OE to “1”.
The algorithm for reading the signature bytes is as follows (refer to “Programming the
Flash” on page 95 for details on command and address loading):
1. A: Load Command “0000 1000”.
2. C: Load Address Low Byte ($00 - $02).
3. Set OE to “1”.
Set OE to “0” and BS to “0”. The selected signature byte can now be read at DATA.
Bit 5 = SPIEN Fuse bit.
Bit 0 = FSTRT Fuse bit.
Bit 7-6,4-1 = “1”. These bits are reserved and should be left unprogrammed (“1”).
is found in Table 40. Programming the Fuse bits does not generate any activity
on the RDY/BSY pin.
Bit 2 = Lock Bit2
Bit 1 = Lock Bit1
Bit 7-3,0 = “1”. These bits are reserved and should be left unprogrammed (“1”).
read at DATA (“0” means programmed).
Bit 7 = Lock Bit1
Bit 6 = Lock Bit2
Bit 5 = SPIEN Fuse bit
Bit 0 = FSTRT Fuse bit
Observe that BS needs to be set to “1”.
t
WLWH_PFB
-wide negative pulse to execute the programming,
t
WLWH_PFB
1041H–11/01