Manual

102
AT90S/LS8535
1041H–11/01
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 42. Serial Programming Instruction Set
Instruction
Instruction Format
OperationByte 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 H000 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 H000 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 xxxa bbbb bbbb oooo oooo Read data o from EEPROM
memory at address a:b.
Write EEPROM Memory
1100 0000 xxxx xxxa 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 12Sx xxxF Read Lock and Fuse bits.
“0” = programmed
“1” = unprogrammed
Write Lock Bits
1010 1100 1111 1211 xxxx xxxx xxxx xxxx Write Lock bits. Set bits 1,2 =
“0” to program Lock bits.
Read Signature Byte
0011 0000 xxxx xxxx xxxx xxbb oooo oooo Read signature byte o at
address b.
(2)
Write FSTRT Fuse
1010 1100 1011 111F xxxx xxxx xxxx xxxx Write FSTRT fuse. Set bit
F = “0” to program,
“1” to unprogram.