ATMEGA88PA_14 Datasheet, PDF (256/326 Pages) ATMEL Corporation – ATMEL 8-BIT MICROCONTROLLER

Table 28-11. Pin Name Mapping
Signal Name in
Programming Mode
Pin Name
RDY/BSY
PD1
OE
PD2
WR
PD3
BS1
PD4
XA0
PD5
XA1
PD6
PAGEL
PD7
BS2
PC2
DATA
{PC[1:0]: PB[5:0]}
I/O Function
O
0: Device is busy programming, 1: Device is ready for
new command
I Output enable (active low)
I Write pulse (active low)
I Byte select 1 (“0” selects low byte, “1” selects high byte)
I XTAL action bit 0
I XTAL action bit 1
I Program memory and EEPROM data page load
I
Byte select 2 (“0” selects low byte, “1” selects 2’nd high
byte)
I/O Bi-directional data bus (output when OE is low)
Table 28-12. Pin Values Used to Enter Programming Mode
Pin
Symbol
PAGEL
Prog_enable[3]
XA1
Prog_enable[2]
XA0
Prog_enable[1]
BS1
Prog_enable[0]
Value
0
0
0
0
Table 28-13. 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 28-14. 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
256 ATmega48PA/88PA/168PA [DATASHEET]
9223F–AVR–04/14