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Port Data Register 9 (PDR9)
Bit
P9
Initial value
Read/Write
R/W
PDR9 is an 8-bit register that stores data for port 9 pins P9
bits are set to 1, the values stored in PDR9 are directly read, regardless of the actual pin states. If
port 9 is read while PCR9 bits are cleared to 0, the pin states are read.
Upon reset, PDR9 is initialized to H'00.
Port Control Register 9 (PCR9)
Bit
PCR9
Initial value
Read/Write
PCR9 is an 8-bit register for controlling whether each of the port 9 pins P9
input or output pin. Setting a PCR9 bit to 1 makes the corresponding pin an output pin, while
clearing the bit to 0 makes the pin an input pin.
Upon reset, PCR9 is initialized to H'00.
PCR9 is a write-only register. All bits are read as 1.
150
7
6
P9
P9
7
6
0
0
R/W
R/W
7
6
PCR9
PCR9
7
6
0
0
W
W
W
5
4
P9
P9
5
4
0
0
R/W
R/W
to P9
7
5
4
PCR9
PCR9
5
4
0
0
W
W
3
2
P9
P9
3
2
0
0
R/W
R/W
. If port 9 is read while PCR9
0
3
2
PCR9
PCR9
3
2
0
0
W
W
to P9
functions as an
7
0
1
0
P9
1
0
0
0
R/W
1
0
PCR9
1
0
0
0
W
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