Table 26-10. XA1 and XA0 Coding
XA1
XA0
Action when XTAL1 is Pulsed
Load Flash or EEPROM Address (High or low address byte determined by
BS1).
0
0
0
1
1
1
0
1
Load Data (High or Low data byte for Flash determined by BS1).
Load Command
No Action, Idle
Table 26-11. Command Byte Bit Coding
Command Byte
1000 0000
0100 0000
0010 0000
0001 0000
0001 0001
0000 1000
0000 0100
0000 0010
0000 0011
Command Executed
Chip Erase
Write Fuse bits
Write Lock bits
Write Flash
Write EEPROM
Read Signature Bytes and Calibration byte
Read Fuse and Lock bits
Read Flash
Read EEPROM
300
ATmega169P
8018A–AVR–03/06