ATMEGA48_11 Datasheet, PDF (290/377 Pages) ATMEL Corporation – High performance, low power Atmel AVR 8-bit microcontroller Advanced RISC architecture

ATmega48/88/168
Figure 28-1. Parallel programming.
RDY/BSY
OE
WR
BS1
XA0
XA1
PAGEL
+12V
BS2
+4.5V - 5.5V
PD1
VCC
PD2
+4.5V - 5.5V
PD3
AVCC
PD4 _{PC[1:0]:PB[5:0]}
PD5
DATA
PD6
PD7
RESET
PC2
XTAL1
GND
Note: V_CC - 0.3V < AV_CC < V_CC + 0.3V, however, AV_CC should always be within 4.5V - 5.5V.
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
DATA
PC2
{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
2545T–AVR–05/11
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