Datasheet

ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
246
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
PAGEL PD7 I Program memory and EEPROM data page load
BS2 PC2 I
Byte select 2 (“0” selects low byte, “1” selects 2’nd
high byte)
DATA {PC[1:0]: PB[5:0]} 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
Table 25-10. 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
GND
XTAL1
PC2
PD1
PD2
PD3
PD4
DATA
PD5
PD6
PD7
RESET
VCC
AVCC
PC[1:0]:PB[5:0]
+ 4.5V to 5.5V
+ 4.5V to 5.5V
RDY/BSY
OE
WR
BS1
XA0
XA1
PAGEL
+12V
BS2