Datasheet

230
7728G–AVR–06/10
ATtiny87/ATtiny167
Table 21-10. Pin Values Used to Enter Programming Mode
Pin Symbol Value
PAGEL / BS1 Prog_enable[3] 0
XA1 / BS2 Prog_enable[2] 0
XA0 Prog_enable[1] 0
WR
Prog_enable[0] 0
Table 21-11. XA1 and XA0 Coding
XA1 XA0 Action when XTAL1 is Pulsed
00
Load Flash or EEPROM Address (High or low address byte determined by
BS1).
0 1 Load Data (High or Low data byte for Flash determined by BS1).
1 0 Load Command
1 1 No Action, Idle
Table 21-12. Command Byte Bit Coding
Command Byte Command Executed
1000 0000
b
Chip Erase
0100 0000
b
Write Fuse bits
0010 0000
b
Write Lock bits
0001 0000
b
Write Flash
0001 0001
b
Write EEPROM
0000 1000
b
Read Signature bytes and Calibration byte
0000 0100
b
Read Fuse and Lock bits
0000 0010
b
Read Flash
0000 0011
b
Read EEPROM