atmega103 ATMEL Corporation, atmega103 Datasheet - Page 106

• Manufacturer Part Number: atmega103
• Description: Atmega103 8-bit With 128k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

106
ATmega103(L)
.
Table 37. Pin Name Mapping
Table 38. XA1 and XA0 Coding
Table 39. Command Byte Bit Coding
XA1
Programming Mode
0
0
1
1
Signal Name in
RDY/BSY
PAGEL
XA0
DATA
BS1
XA0
XA1
BS2
WR
0
1
0
1
OE
Command Byte
1000 0000
0100 0000
0010 0000
0001 0000
0001 0001
0000 1000
0000 0100
0000 0010
0000 0011
Action when XTAL1 is Pulsed
Load Flash or EEPROM Address (High or low address byte determined by BS1)
Load Data (High or low data byte for Flash determined by BS1)
Load Command
No Action, Idle
Pin Name
PB7 - 0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
PA0
I/O
I/O
O
I
I
I
I
I
I
I
Read Flash
Read EEPROM
Command Executed
Chip Erase
Write Fuse Bits
Write Lock Bits
Write Flash
Write EEPROM
Read Signature Bytes
Read Lock and Fuse Bits
Function
0: Device is busy programming, 1: Device is ready
for new command
Output Enable (active low)
Write Pulse (active low)
Byte Select 1 (“0” selects Low Byte, “1” selects
High Byte)
XTAL Action Bit 0
XTAL Action Bit 1
Byte Select 2 (always low)
Program Memory Page Load
Bi-directional Data Bus (output when OE is low)
0945I–AVR–02/07