Datasheet

Table Of Contents
Section 9 I/O Ports
Rev. 2.00 Jul. 04, 2007 Page 167 of 692
REJ09B0309-0200
9.3.2 Port Control Register 4 (PCR4)
PCR4 selects inputs/outputs in bit units for pins to be used as general I/O ports of
port 4.
Bit Bit Name
Initial
Value
R/W Description
7 to 3 All 1 Reserved
These bits are always read as 1 and cannot be
modified.
2
1
0
PCR42
PCR41
PCR40
0
0
0
W
W
W
Setting a PCR4 bit to 1 makes the corresponding pin an
output pin, while clearing the bit to 0 makes the pin an
input pin. The settings in PCR4 and in PDR4 are valid
when the corresponding pin is designated as a general
I/O pin.
PCR4 is a write-only register. These bits are always
read as 1.