HD6433802H Datasheet, PDF (152/435 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

1. Port data register 3 (PDR3)
Bit
7
6
5
4
3
2
1
0
P3 ₇
P3₆
P3₅
P3₄
P3 ₃
P3₂
P3₁
—
Initial value
0
0
0
0
0
0
0
—
Read/Write
R/W
R/W R/W
R/W R/W R/W
R/W
—
PDR3 is an 8-bit register that stores data for port 3 pins P3₇ to P3₁. If port 3 is read while PCR3
bits are set to 1, the values stored in PDR3 are read, regardless of the actual pin states. If port 3 is
read while PCR3 bits are cleared to 0, the pin states are read.
2. Port control register 3 (PCR3)
Bit
7
6
5
4
3
2
1
0
PCR3₇ PCR3₆ PCR3₅ PCR3₄ PCR3₃ PCR3₂ PCR3₁
—
Initial value
0
0
0
0
0
0
0
—
Read/Write
W
W
W
W
W
W
W
W
PCR3 is an 8-bit register for controlling whether each of the port 3 pins P3₇ to P3₁ functions as an
input pin or output pin. Setting a PCR3 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 PCR3 and in PDR3 are valid only
when the corresponding pin is designated in PMR3 as a general I/O pin.
PCR3 is a write-only register. Bits 7 to 1 are always read as 1. Bit 0 is reserved; only 0 can be
written to this bit.
3. Port pull-up control register 3 (PUCR3)
Bit
7
6
5
4
3
2
1
0
PUCR3₇ PUCR3₆ PUCR3₅ PUCR3₄ PUCR3₃ PUCR3₂ PUCR3₁ —
Initial value
0
0
0
0
0
0
0
—
Read/Write
R/W
R/W R/W
R/W R/W R/W
R/W
W
PUCR3 controls whether the MOS pull-up of each of the port 3 pins P3₇ to P3₁ is on or off. When
a PCR3 bit is cleared to 0, setting the corresponding PUCR3 bit to 1 turns on the MOS pull-up for
the corresponding pin, while clearing the bit to 0 turns off the MOS pull-up.
Bit 0 is reserved; only 0 can be written to this bit.
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