Datasheet
Section 9 I/O Ports
Rev.4.00 Nov. 02, 2005 Page 100 of 304
REJ09B0143-0400
9.2 Port 2
Port 2 is a general I/O port also functioning as a SCI3 I/O pin. Each pin of the port 2 is shown in
figure 9.2. The register settings of PMR1 and SCI3 have priority for functions of the pins for both
uses.
P22/TXD
P21/RXD
P20/SCK3
Port 2
Figure 9.2 Port 2 Pin Configuration
Port 2 has the following registers.
• Port control register 2 (PCR2)
• Port data register 2 (PDR2)
9.2.1 Port Control Register 2 (PCR2)
PCR2 selects inputs/outputs in bit units for pins to be used as general I/O ports of port 2.
Bit Bit Name Initial Value R/W Description
7
6
5
4
3
Reserved
2
1
0
PCR22
PCR21
PCR20
0
0
0
W
W
W
When each of the port 2 pins P22 to P20 functions as an
general I/O port, setting a PCR2 bit to 1 makes the
corresponding pin an output port, while clearing the bit to 0
makes the pin an input port.