Hitachi H8/3048 Hardware Manual page 261

In modes 5 to 7, P1DDR is a write-only register. Its value cannot be read. All bits return 1 when
read.
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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.
Bit 7
P1
7
Initial value 0
Read/Write R/W
P1DR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
6 5 4
P1 P1 P1
6 5 4
0 0 0
R/W R/W R/W
Port 1 data 7 to 0
These bits store data for port 1 pins
248
3 2 1
P1 P1 P1
3 2 1
0 0 0
R/W R/W R/W
0
P1
0
0
R/W