Datasheet

Rev.6.00 Oct.28.2004 page 289 of 1016
REJ09B0138-0600H
9.4 Port 3
9.4.1 Overview
Port 3 is a 6-bit I/O port. Port 3 pins also function as SCI I/O pins (TxD0, RxD0, SCK0, TxD1, RxD1, and SCK1). Port 3
pin functions are the same in all operating modes.
Figure 9-3 shows the port 3 pin configuration.
P3
5
P3
4
P3
3
P3
2
P3
1
P3
0
(I/O)/
(I/O)/
(I/O)/
(I/O)/
(I/O)/
(I/O)/
SCK1 (I/O)
SCK0 (I/O)
RxD1 (input)
RxD0 (input)
TxD1 (output)
TxD0 (output)
Port 3 pins
Port 3
Figure 9-3 Port 3 Pin Functions
9.4.2 Register Configuration
Table 9-6 shows the port 3 register configuration.
Table 9-6 Port 3 Registers
Name Abbreviation R/W Initial Value*
2
Address*
1
Port 3 data direction register P3DDR W H'00 H'FEB2
Port 3 data register P3DR R/W H'00 H'FF62
Port 3 register PORT3 R Undefined H'FF52
Port 3 open drain control register P3ODR R/W H'00 H'FF76
Notes: 1. Lower 16 bits of the address.
2. Value of bits 5 to 0.
Port 3 Data Direction Register (P3DDR)
Bit:76543210
— — P35DDR P34DDR P33DDR P32DDR P31DDR P30DDR
Initial value : Undefined Undefined 000000
R/W:——WWWWWW
P3DDR is an 8-bit write-only register, the individual bits of which specify input or output for the pins of port 3. Bits 7 and
6 are reserved. P3DDR cannot be read; if it is, an undefined value will be read.
Setting a P3DDR bit to 1 makes the corresponding port 3 pin an output pin, while clearing the bit to 0 makes the pin an
input pin.