ATmega8(L)
Table 98. Serial Programming Instruction Set
Instruction Format
Instruction
Byte 1
Byte 2
Byte 3
Byte4
Operation
Programming Enable
1010 1100
0101 0011
xxxx xxxx
xxxx xxxx
Enable Serial Programming after
RESET goes low.
Chip Erase
1010 1100
100x xxxx
xxxx xxxx
xxxx xxxx
Chip Erase EEPROM and Flash.
Read Program Memory
0010 H000
0000 aaaa
bbbb bbbb
oooo oooo
Read H (high or low) data o from
Program memory at word address
a:b.
Load Program Memory
Page
0100 H000
0000 xxxx
xxxb bbbb
iiii iiii
Write H (high or low) data i to
Program memory page at word
address b. Data Low byte must be
loaded before Data High byte is
applied within the same address.
Write Program Memory
Page
0100 1100
1010 0000
1100 0000
0101 1000
0000 aaaa
00xx xxxa
00xx xxxa
0000 0000
bbbx xxxx
bbbb bbbb
bbbb bbbb
xxxx xxxx
xxxx xxxx
oooo oooo
iiii iiii
xxoo oooo
Write Program memory Page at
address a:b.
Read EEPROM Memory
Write EEPROM Memory
Read Lock Bits
Read data o from EEPROM
memory at address a:b.
Write data i to EEPROM memory at
address a:b.
Read Lock Bits. “0” = programmed,
“1” = unprogrammed. See Table
85 on page 219 for details.
Write Lock Bits
1010 1100
111x xxxx
xxxx xxxx
11ii iiii
Write Lock Bits. Set bits = “0” to
program Lock Bits. See Table 85
on page 219 for details.
Read Signature Byte
Write Fuse Bits
0011 0000
1010 1100
00xx xxxx
1010 0000
xxxx xxbb
oooo oooo
iiii iiii
Read Signature Byte o at address
b.
xxxx xxxx
Set bits = “0” to program, “1” to
unprogram. See Table 88 on
page 221 for details.
Write Fuse High Bits
Read Fuse Bits
1010 1100
0101 0000
0101 1000
1010 1000
0000 0000
0000 1000
xxxx xxxx
xxxx xxxx
xxxx xxxx
iiii iiii
oooo oooo
oooo oooo
Set bits = “0” to program, “1” to
unprogram. See Table 87 on
page 220 for details.
Read Fuse Bits. “0” = programmed,
“1” = unprogrammed. See Table
88 on page 221 for details.
Read Fuse High Bits
Read Fuse high bits. “0” = pro-
grammed, “1” = unprogrammed.
See Table 87 on page 220 for
details.
Read Calibration Byte
0011 1000
00xx xxxx
0000 00bb
oooo oooo
Read Calibration Byte
Note:
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
235
2486M–AVR–12/03
ATMEL [ ATMEL ]
