ATmega325PA Atmel Corporation, ATmega325PA Datasheet - Page 287

• Manufacturer Part Number: ATmega325PA
• Manufacturer: Atmel Corporation

27.6
27.6.1
8285D–AVR–06/11
Parallel Programming Parameters, Pin Mapping, and Commands
Signal Names
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
This section describes how to parallel program and verify Flash Program memory, EEPROM
D a t a
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P. Pulses are
assumed to be at least 250 ns unless otherwise noted.
I n t h i s s e c t i o n , s o m e p i n s o f t h e
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P are referenced by
signal names describing their functionality during parallel programming, see
Table
The XA1/XA0 pins determine the action executed when the XTAL1 pin is given a positive pulse.
The bit coding is shown in
When pulsing WR or OE, the command loaded determines the action executed. The different
Commands are shown in
Figure 27-1. Parallel Programming
Table 27-9.
Programming Mode
Signal Name in
27-9. Pins not described in the following table are referenced by pin names.
RDY/BSY
BS1
XA0
XA1
WR
OE
m e m o r y ,
Pin Name Mapping
Pin Name
M e m o r y
RDY/BSY
Table
PD1
PD2
PD3
PD4
PD5
PD6
Table
PAGEL
+12 V
BS2
BS1
XA0
XA1
WR
OE
27-12.
27-11.
I/O
O
I
I
I
I
I
L o c k
PD1
PD2
PD3
PD4
PD5
PD6
PD7
RESET
XTAL1
GND
PA0
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
b i t s ,
PB7 - PB0
AVCC
VCC
a n d
+5V
+5V
DATA
F u s e
b i t s
Figure 27-1
i n
and
287
t h e