HD6433802H Datasheet, PDF (158/435 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

2. Port control register 4 (PCR4)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
— PCR4₂ PCR4₁ PCR4 ₀
Initial value
1
1
1
1
1
0
0
0
Read/Write
—
—
—
—
—
W
W
W
PCR4 is an 8-bit register for controlling whether each of port 4 pins P4₂ to P4₀ functions as an
input pin or output pin. Setting a PCR4 bit to 1 makes the corresponding pin an output pin, while
clearing the bit to 0 makes the pin an input pin. PCR4 and PDR4 settings are valid when the
corresponding pins are designated for general-purpose input/output by SCR3-2.
Upon reset, PCR4 is initialized to H'F8.
PCR4 is a write-only register, which is always read as all 1s.
3. Port mode register 2 (PMR2)
Bit
7
6
5
4
3
2
1
0
—
—
POF1
—
—
—
—
IRQ₀
Initial value
1
1
0
1
1
—
—
0
Read/Write
—
—
R/W
—
—
W
W
R/W
PMR2 is an 8-bit read/write register controlling the selection of the P43/IRQ0 pin function and the
PMOS on/off state for the P3₅ pin. Upon reset, PMR2 is initialized to H'DE.
Bits 7, 6, 4, and 3: Reserved bits
Bits 7, 6, and 4 to 1 are reserved; they are always read as 1 and cannot be modified.
Bit 5: P3₅ pin PMOS control (POF1)
This bit controls the on/off state of the P3₅ pin output buffer PMOS.
Bit 5
POF1
0
1
Description
CMOS output
NMOS open-drain output
(initial value)
Bits 2 and 1: Reserved bits
Bits 2 and 1 are reserved; only 0 can be written to these bits.
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