111
ATtiny26(L)
1477G–AVR–03/05
Note:
1. [XA1, XA0] = 0b11 is “No Action, Idle”. As long as XTAL1 is not pulsed, the Com-
mand, Address, and Data Registers remain unchanged. Therefore, there are no
problems using BS2 as described below even though BS2 is multiplexed with XA1.
BS2 is only asserted when reading the fuses (OE is low) and XTAL1 is not pulsed.
Table 56. XA1 and XA0 Coding
XA1
XA0
Action when XTAL1 is Pulsed
0
0
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 57. Command Byte Bit Coding
Command Byte
Command Executed
1000 0000
Chip Erase
0100 0000
Write Fuse Bits
0010 0000
Write Lock Bits
0001 0000
Write Flash
0001 0001
Write EEPROM
0000 1000
Read Signature Bytes and Calibration Byte
0000 0100
Read Fuse and Lock Bits
0000 0010
Read Flash
0000 0011
Read EEPROM