Datasheet

Section 9 I/O Ports
Rev. 1.50 Sep. 18, 2007 Page 131 of 584
REJ09B0240-0150
9.2 Port 2
Port 2 is a general I/O port also functioning as SCI3 I/O pins. Each pin of 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
P23
P24
P25
P26
P27
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)
• Port mode register 3 (PMR3)
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
2
1
0
PCR27
PCR26
PCR25
PCR24
PCR23
PCR22
PCR21
PCR20
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
When each of the port 2 pins P24 to P20 functions as a
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.