HD6433832S Datasheet, PDF (168/560 Pages) Renesas Technology Corp – single-chip microcomputers

Port Data Register 4 (PDR4)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
P4₃
P4₂
P4₁
P4₀
Initial value
1
1
1
1
1
0
0
0
Read/Write
—
—
—
—
R
R/W
R/W
R/W
PDR4 is an 8-bit register that stores data for port 4 pins P4₂ to P4₀. If port 4 is read while PCR4
bits are set to 1, the values stored in PDR4 are read, regardless of the actual pin states. If port 4 is
read while PCR4 bits are cleared to 0, the pin states are read.
Upon reset, PDR4 is initialized to H'F8.
Port Control Register 4 (PCR4)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
—
PCR4₂ PCR4₁ PCR4₀
Initial value
1
1
1
1
1
0
0
0
Read/Write
—
—
—
—
—
W
W
W
PCR4 controls whether each of the 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. The settings in PCR4 and in PDR4 are valid only when the
corresponding pin is designated in SCR3 as a general I/O pin.
Upon reset, PCR4 is initialized to H'F8.
PCR4 is a write-only register. All bits are read as 1.
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