AT90S/LS2333 and AT90S/LS4433
76
Programming the EEPROM
The programming algorithm for the EEPROM data memory is as follows (refer to Programming the Flash for details on
Command, Address and Data loading):
1.
A: Load Command ‘0001 0001’.
2.
C: Load Address Low Byte ($00 - $7F/$FF).
3.
D: Load Data Low Byte ($00 - $FF).
4.
E: Write Data Low Byte.
Reading the EEPROM
The algorithm for reading the EEPROM memory is as follows (refer to Programming the Flash for details on Command and
Address loading):
1.
A: Load Command ‘0000 0011’.
2.
C: Load Address Low Byte ($00 - $7F/$FF).
3.
Set OE to ‘0’, and BS to ‘0’. The EEPROM data byte can now be read at DATA.
4.
Set OE to ‘1’.
Programming the Fuse Bits
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.
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
Bit 7-6 = ‘1’. These bits are reserved and should be left unprogrammed (‘1’).
3.
Give WR a
t
WLWH_PFB
wide negative pulse to execute the programming,
t
WLWH_PFB
is found in Table 33. Programming
the Fuse bits does not generate any activity on the RDY/BSY pin.
Programming the Lock Bits
The algorithm for programming the Lock bits is as follows (refer to Programming the Flash 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.
Bit 2 = Lock Bit2
Bit 1 = Lock Bit1
Bit 7-3,0 = ‘1’. These bits are reserved and should be left unprogrammed (‘1’).
3.
E: Write Data Low Byte.
The Lock bits can only be cleared by executing Chip Erase.
Reading the Fuse and Lock Bits
The algorithm for reading the Fuse and Lock bits is as follows (refer to Programming the Flash for details on Command
loading):
1.
A: Load Command ‘0000 0100’.
2.
Set OE to ‘0’, and BS to ‘0’. The status of the Fuse bits can now be read at DATA (‘0’ means programmed).