297
4317I–AVR–01/08
AT90PWM2/3/2B/3B
Figure 25-11. Serial Programming Waveforms
MSB
MSB
LSB
LSB
SERIAL CLOCK INPUT
(SCK)
SERIAL DATA INPUT
(MOSI)
(MISO)
SAMPLE
SERIAL DATA OUTPUT
Table 25-16. 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 after
RESET goes low.
Chip Erase
1010 1100
100x xxxx
xxxx xxxx
xxxx xxxx
Chip Erase EEPROM and Flash.
Read Program Memory
0010
H
000
000
a
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
H
000
000x xxxx
xx
bb 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
000
a
aaaa
bb
xx xxxx
xxxx xxxx
Write Program Memory Page at
address a:b.
Read EEPROM Memory
1010 0000
000x xx
aa
bbbb bbbb
oooo oooo
Read data o from EEPROM memory at
address a:b.
Write EEPROM Memory
1100 0000
000x xx
aa
bbbb bbbb
iiii iiii
Write data i to EEPROM memory at
address a:b.
Load EEPROM Memory
Page (page access)
1100 0001
0000 0000
0000 00
bb
iiii iiii
Load data i to EEPROM memory page
buffer. After data is loaded, program
EEPROM page.
Write EEPROM Memory
Page (page access)
1100 0010
00xx xx
aa
bbbb bb00
xxxx xxxx
Write EEPROM page at address a:b.
Read Lock bits
0101 1000
0000 0000
xxxx xxxx
xx
oo oooo
Read Lock bits. “0” = programmed, “1”
= unprogrammed. See
for details.
Write Lock bits
1010 1100
111x xxxx
xxxx xxxx
11
ii iiii
Write Lock bits. Set bits = “0” to
program Lock bits. See
for details.
Read Signature Byte
0011 0000
000x xxxx
xxxx xx
bb
oooo oooo
Read Signature Byte o at address b.
Write Fuse bits
1010 1100
1010 0000
xxxx xxxx
iiii iiii
Set bits = “0” to program, “1” to
unprogram. See Table XXX on page
XXX for details.