HD64F3437TF16 Datasheet, PDF (147/752 Pages) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

Port 3 Data Register (P3DR)
Bit
7
P3₇
Initial value
0
Read/Write R/W
6
P3₆
0
R/W
5
P3₅
0
R/W
4
P3₄
0
R/W
3
P3₃
0
R/W
2
P3₂
0
R/W
1
P3₁
0
R/W
0
P3₀
0
R/W
P3DR is an 8-bit register that stores data for pins P3₇ to P3₀. When a P3DDR bit is set to 1, if port
3 is read, the value in P3DR is obtained directly, regardless of the actual pin state. When a P3DDR
bit is cleared to 0, if port 3 is read the pin state is obtained.
P3DR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its existing values.
Port 3 Input Pull-Up Control Register (P3PCR)
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0
P3₇PCR P3₆PCR P3₅PCR P3₄PCR P3₃PCR P3₂PCR P3₁PCR P3₀PCR
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
P3PCR is an 8-bit readable/writable register that controls the input pull-up transistors in port 3. If
a P3DDR bit is cleared to 0 (designating input) and the corresponding P3PCR bit is set to 1, the
input pull-up transistor is turned on.
P3PCR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its existing values.
The input pull-ups cannot be used in slave mode (when the host interface is enabled).
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