Datasheet

Table Of Contents
283
2570N–AVR–05/11
ATmega325/3250/645/6450
Notes: 1. Not all instructions are applicable for all parts
2. a = address
3. Bits are programmed ‘0’, unprogrammed ‘1’.
4. To ensure future compatibility, unused Fuses and Lock bits should be unprogrammed (‘1’) .
5. Refer to the correspondig section for Fuse and Lock bits, Calibration and Signature bytes and
Page size.
6. See htt://www.atmel.com/avr for Application Notes regarding programming and programmers.
If the LSB in RDY/BSY data byte out is ‘1’, a programming operation is still pending. Wait until
this bit returns ‘0’ before the next instruction is carried out.
Within the same page, the low data byte must be loaded prior to the high data byte.
After data is loaded to the page buffer, program the EEPROM page, see Figure 27-12.
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
Write Program Memory Page $4C adr MSB adr LSB $00
Write EEPROM Memory $C0 0000 00aa
/
0000 0aaa
aaaa aaaa data byte in
Write EEPROM Memory Page (page access) $C2 0000 00aa
/
0000 0aaa
aaaa aa00
/
aaaa a000
$00
Write Lock bits $AC $E0 $00 data byte in
Write Fuse bits $AC $A0 $00 data byte in
Write Fuse High bits $AC $A8 $00 data byte in
Write Extended Fuse Bits $AC $A4 $00 data byte in
Table 27-15. Serial Programming Instruction Set
Instruction/Operation
Instruction Format
Byte 1 Byte 2 Byte 3 Byte4