AT90S/LS4434 and AT90S/LS8535
95
f
Notes:
1.
a
= address high bits
b
= address low bits
H
= 0 – Low byte, 1 – High Byte
o
= data out
i
= data in
x = don’t care
1
= Lock Bit 1
2
= Lock Bit 2
F
= FSTRT Fuse
S
= SPIEN Fuse
2. The signature bytes are not readable in lock mode 3, i.e., both Lock bits programmed.
Table 43.
Serial Programming Instruction Set
Instruction
Instruction Format
Operation
Byte 1
Byte 2
Byte 3
Byte4
Programming Enable
1010 1100
0101 0011
xxxx xxxx
xxxx xxxx
Enable serial programming
while RESET is low.
Chip Erase
1010 1100
100x xxxx
xxxx xxxx
xxxx xxxx
Chip Erase Flash and
EEPROM memory arrays.
Read Program Memory
0010
H
000
xxxx
aaaa
bbbb bbbb
oooo oooo
Read
H
(high or low) data
o
from program memory at word
address
a
:
b
.
Write Program Memory
0100
H
000
xxxx
aaaa
bbbb bbbb
iiii iiii
Write
H
(high or low) data
i
to
program memory at word
address
a
:
b
.
Read EEPROM Memory
1010 0000
xxxx xxx
a
bbbb bbbb
oooo oooo
Read data
o
from EEPROM
memory at address
a
:
b
.
Write EEPROM Memory
1100 0000
xxxx xxx
a
bbbb bbbb
iiii iiii
Write data
i
to EEPROM
memory at address
a
:
b
.
Read Lock and Fuse Bits
0101 1000
xxxx xxxx
xxxx xxxx
12
S
x xxx
F
Read Lock and Fuse bits.
“0” = programmed
“1” = unprogrammed
Write Lock Bits
1010 1100
1111 1
21
1
xxxx xxxx
xxxx xxxx
Write Lock bits. Set bits
1
,
2
=
“0” to program Lock bits.
Read Signature Byte
0011 0000
xxxx xxxx
xxxx xx
bb
oooo oooo
Read signature byte
o
at
address
b
.
Write FSTRT Fuse
1010 1100
1011 111
F
xxxx xxxx
xxxx xxxx
Write FSTRT fuse. Set bit
F
= “0” to program,
“1” to unprogram.