302
7647H–AVR–03/12
Atmel ATmega16/32/64/M1/C1
Figure 25-1. Parallel Programming
Table 25-8. 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 EL PD7 I
Program memory and EEPROM Data Page
Load
BS2 PE2 I
Byte Select 2 (“0” selects Low byte, “1” selects
2’nd High byte)
DATA PB[7:0] I/O
Bi-directional Data bus (Output when OE is
low)
Table 25-9. 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
VCC
GND
XTAL1
XA0
RDY/BSY
OE
RESET
+ 5V
AVCC
+ 5V
PD1
+ 12 V
PD7
PD6
PD5
PD4
PD3
PD2
PE2
WR
XA1
BS2
PAGEL
BS1
DATA
PB[7:0]