Atmel ATmega328 User Manual

304
8271D–AVR–05/11
ATmega48A/PA/88A/PA/168A/PA/328/P
Table 28-13. Pin Name Mapping
Signal Name in
Programming Mode Pin Name I/O Function
RDY/BSY PD1 O
0: Device is busy programming, 1: Device is
ready for new command
OE
PD2 I Output Enable (Active low)
WR
PD3 I Write Pulse (Active low)
BS1 PD4 I
Byte Select 1 (“0” selects Low byte, “1” selects
High byte)
XA0 PD5 I XTAL Action Bit 0
XA1 PD6 I XTAL Action Bit 1
PAG E L PD7 I
Program memory and EEPROM Data Page
Load
BS2 PC2 I
Byte Select 2 (“0” selects Low byte, “1” selects
2’nd High byte)
DATA {PC[1:0]: PB[5:0]} I/O Bi-directional Data bus (Output when OE is low)
Table 28-14. Pin Values Used to Enter Programming Mode
Pin Symbol Value
PAGEL Prog_enable[3] 0
XA1 Prog_enable[2] 0
XA0 Prog_enable[1] 0
BS1 Prog_enable[0] 0
Table 28-15. 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 28-16. 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

Atmel ATmega328 Specifications

General

Brand	Atmel
Model	ATmega328
Category	Microcontrollers
Language	English