45
AT90S/LS2323/2343
1004D–09/01
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
R = RCEN Fuse
S = SPIEN Fuse
2. When the state of the RCEN/FSTRT bit is changed, the device must be power cycled for the changes to have any effect.
3. The signature bytes are not readable in Lock mode 3, i.e., both Lock bits programmed.
Table 19. Low-voltage Serial Programming Instruction Set AT90S2323/2343
Instruction
Instruction Format
OperationByte 1 Byte 2 Byte 3 Byte 4
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 both Flash and
EEPROM memory arrays.
Read Program
Memory
0010 H000 0000 00aa bbbb bbbb oooo oooo Read H (high or low) data o from
program memory at word address
a:b.
Write Program
Memory
0100 H000 0000 00aa bbbb bbbb iiii iiii Write H (high or low) data i to
program memory at word address
a:b.
Read
EEPROM Memory
1010 0000 0000 0000 xbbb bbbb oooo oooo Read data o from EEPROM
memory at address b.
Write
EEPROM Memory
1100 0000 0000 0000 xbbb bbbb iiii iiii Write data i to EEPROM memory at
address b.
Read Lock and
Fuse Bits
(AT90S/LS2323)
0101 1000 xxxx xxxx xxxx xxxx 12Sx xxxF Read Lock and Fuse bits.
“0” = programmed,
“1” = unprogrammed
Read Lock and
Fuse Bits
(AT90S/LS2343)
0101 1000 xxxx xxxx xxxx xxxx 12Sx xxxR 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.
Write FSTRT Bit
(AT90S/LS2323)
1010 1100 1011 111F xxxx xxxx xxxx xxxx Write FSTRT fuse. Set bit F = “0” to
program, “1” to unprogram.
(2)
Write RCEN Bit
(AT90S/LS2343)
1010 1100 1011 111R xxxx xxxx xxxx xxxx Write RCEN Fuse. Set bit R = ‘0’ to
program, ‘1’ to unprogram.
(2)
Read Signature
Bytes
0011 0000 xxxx xxxx xxxx xxbb oooo oooo Read signature byte o from
address b.
(3)