In modes 5 to 7, P1DDR is a write-only register. Its value cannot be read. All bits return 1 when
read.
P1DDR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode
it retains its previous setting. If a P1DDR bit is set to 1, the corresponding pin maintains its output
state in software standby mode.
Port 1 Data Register (P1DR): P1DR is an 8-bit readable/writable register that stores port 1
output data. When this register is read, the pin logic level of a pin is read for bits for which the
P1DDR setting is 0, and the P1DR value is read for bits for which the P1DDR setting is 1.
P1DR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
Bit
Initial value
Read/Write
7
P1
0
R/W
Port 1 data 7 to 0
These bits store data for port 1 pins
7
6
P1
0
R/W
6
5
P1
0
R/W
5
4
P1
0
R/W
4
3
P1
0
R/W
3
2
P1
0
R/W
2
1
P1
0
R/W
1
0
P1
0
R/W
0
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