301
2545M–AVR–09/07
ATmega48/88/168
6. Any memory location can be verified by using the Read instruction which returns the con-
tent at the selected address at serial output MISO.
7. At the end of the programming session, RESET
can be set high to commence normal
operation.
8. Power-off sequence (if needed):
Set RESET
to “1”.
Turn V
CC
power off.
27.8.3 Serial Programming Instruction set
Table 27-17 on page 301 and Figure 27-8 on page 302 describes the Instruction set.
Table 27-16. Typical Wait Delay Before Writing the Next Flash or EEPROM Location
Symbol Minimum Wait Delay
t
WD_FLASH
4.5 ms
t
WD_EEPROM
3.6 ms
t
WD_ERASE
9.0 ms
Table 27-17. Serial Programming Instruction Set (Hexadecimal values)
Instruction/Operation
Instruction Format
Byte 1 Byte 2 Byte 3 Byte4
Programming Enable $AC $53 $00 $00
Chip Erase (Program Memory/EEPROM) $AC $80 $00 $00
Poll RDY/BSY
$F0 $00 $00 data byte out
Load Instructions
Load Extended Address byte
(1)
$4D $00 Extended adr $00
Load Program Memory Page, High byte $48 $00 adr LSB high data byte in
Load Program Memory Page, Low byte $40 $00 adr LSB low data byte in
Load EEPROM Memory Page (page access) $C1 $00 0000 000aa data byte in
Read Instructions
Read Program Memory, High byte $28 adr MSB adr LSB high data byte out
Read Program Memory, Low byte $20 adr MSB adr LSB low data byte out
Read EEPROM Memory $A0 0000 00aa aaaa aaaa data byte out
Read Lock bits $58 $00 $00 data byte out
Read Signature Byte $30 $00 0000 000aa data byte out
Read Fuse bits $50 $00 $00 data byte out
Read Fuse High bits $58 $08 $00 data byte out
Read Extended Fuse Bits $50 $08 $00 data byte out
Read Calibration Byte $38 $00 $00 data byte out
Write Instructions
(6)
Write Program Memory Page $4C adr MSB adr LSB $00
Write EEPROM Memory $C0 0000 00aa aaaa aaaa data byte in
