1.
Port data register 1 (PDR1)
PDR1 is an 8-bit register that stores data for port 1 pins P1
7
to P1
0
. If port 1 is read while PCR1
bits are set to 1, the values stored in PDR1 are read, regardless of the actual pin states. If port 1 is
read while PCR1 bits are cleared to 0, the pin states are read.
Upon reset, PDR1 is initialized to H'00.
2.
Port control register 1 (PCR1)
PCR1 is an 8-bit register for controlling whether each of the port 1 pins P1
7
to P1
0
functions as an
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, which is always read as all 1s.
Bit
Initial value
Read/Write
7
PCR1
0
W
6
PCR1
0
W
5
PCR1
0
W
4
PCR1
0
W
3
PCR1
0
W
0
PCR1
0
W
2
PCR1
0
W
1
PCR1
0
W
7
6
5
4
3
2
1
0
Bit
Initial value
Read/Write
7
P1
0
R/W
6
P1
0
R/W
5
P1
0
R/W
4
P1
0
R/W
3
P1
0
R/W
0
P1
0
R/W
2
P1
0
R/W
1
P1
0
R/W
7
6
5
4
3
2
1
0
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