
297
7530J–AVR–03/12
Atmel ATmega48/88/168 Automotive
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
25.8.4
SPI Serial Programming Characteristics
Read Signature Byte
0011
0000
000x
xxxx
xxbb
oooo
Read Signature Byte o at
address b.
Write Fuse bits
1010
1100
1010
0000
xxxx
iiii
Set bits = “0” to program, “1”
to unprogram. See Table
XXX on page XXX for details.
Write Fuse High bits
1010
1100
1010
1000
xxxx
iiii
Set bits = “0” to program, “1”
Write Extended Fuse
Bits
1010
1100
1010
0100
xxxx
xxxx
xxii
Set bits = “0” to program, “1”
to unprogram. See
details.
Read Fuse bits
0101
0000
xxxx
oooo
Read Fuse bits. “0” =
programmed, “1” =
unprogrammed. See Table
XXX on page XXX for details.
Read Fuse High bits
0101
1000
0000
1000
xxxx
oooo
Read Fuse High bits. “0” =
pro-grammed, “1” =
Read Extended Fuse
Bits
0101
0000
1000
xxxx
oooo
Read Extended Fuse bits. “0”
= pro-grammed, “1” =
Read Calibration Byte
0011
1000
000x
xxxx
0000
oooo
Read Calibration Byte
Poll RDY/BSY
1111
0000
xxxx
xxxo
If o = “1”, a programming
operation is still busy. Wait
until this bit returns to “0”
before applying another
command.
Table 25-17. Serial Programming Instruction Set
Instruction
Instruction Format
Operation
Byte 1
Byte 2
Byte 3
Byte4