HD6413308 Hitachi Semiconductor, HD6413308 Datasheet - Page 100

• Manufacturer Part Number: HD6413308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: Hitachi Semiconductor

pins. They can also drive a Darlington pair. When they are used as input pins, they have
programmable MOS pull-ups.
Table 5-7 details the port 3 registers.
Table 5-7. Port 3 Registers
Name
Port 3 data direction register P3DDR
Port 3 data register
Port 3 Data Direction Register (P3DDR)—H’FFB4
Bit
Initial value
Read/Write
P3DDR is an 8-bit register that selects the direction of each pin in port 3. A pin functions as an
output pin if the corresponding bit in P3DDR is set to “1,” and as an input pin if the bit is cleared to
“0.”
Port 3 Data Register (P3DR)—H’FFB6
Bit
Initial value
Read/Write
P3DR is an 8-bit register containing the data for pins P3
output pins it reads the value in the P3DR latch, but for input pins, it obtains the logic level directly
from the pin, bypassing the P3DR latch.
MOS Pull-Ups: Are available for input pins in mode 3 when the dual-port RAM is disabled.
Software can turn on the MOS pull-up on by writing a “1” in P3DR, and turn it off by writing a
“0.”
P3
R/W
7
P3
W
DDR P3
7
0
7
0
7
R/W
6
P3
Abbreviation
P3DR
W
DDR P3
6
0
6
0
6
R/W
5
P3
W
DDR P3
5
0
5
0
5
Read/Write Initial value
W
R/W
R/W
85
4
P3
W
DDR P3
4
0
4
0
4
7
to P3
R/W
3
P3
W
DDR P3
3
0
3
0
3
H’00
H’00
0
. When the CPU reads P3DR, for
R/W
2
P3
W
DDR P3
2
0
2
0
2
R/W
1
P3
W
Address
H’FFB4
H’FFB6
DDR P3
1
0
1
0
1
R/W
0
P3
W
DDR
0
0
0
0
0