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8. I/O Ports
Port Control Register 1 (PCR1)
PCR1 is an 8-bit register for controlling whether each of the port 1 pins P1
input pin or output pin. Setting a PCR1 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 PCR1 and in PDR1 are valid only
when the corresponding pin is designated in PMR1 as a general I/O pin.
Upon reset, PCR1 is initialized to H'00.
PCR1 is a write-only register. All bits are read as 1.
H8/3857 Group
Bit
PCR1
Initial value
Read/Write
H8/3854 Group
Bit
PCR1
Initial value
Read/Write
In the H8/3854 Group, bits 6, 4, and 3 are reserved, and must always be set to 0.
Rev.3.00 Jul. 19, 2007 page 174 of 532
REJ09B0397-0300
7
6
5
PCR1
PCR1
7
6
0
0
0
W
W
W
7
6
5
⎯
PCR1
7
0
0
0
⎯
W
W
4
3
PCR1
PCR1
5
4
3
0
0
W
W
4
3
⎯
⎯
5
0
0
⎯
⎯
to P1
functions as an
7
0
2
1
PCR1
PCR1
PCR1
2
1
0
0
W
W
2
1
PCR1
PCR1
PCR1
2
1
0
0
W
W
0
0
0
W
0
0
0
W
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