H83644 Datasheet, PDF (191/508 Pages) Hitachi Semiconductor – H8/3644 Series Hardware Manual

PDR3 is an 8-bit register that stores data for port 3 pins P3₂ to P3₀. 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.
Upon reset, PDR3 is initialized to H'00.
Port Control Register 3 (PCR3)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
—
PCR3₂ PCR3₁ PCR3₀
Initial value
0
0
0
0
0
0
0
0
Read/Write
—
—
—
—
—
W
W
W
PCR3 is an 8-bit register for controlling whether each of the port 3 pins P3₂ to P3₀ 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.
Upon reset, PCR3 is initialized to H'00.
PCR3 is a write-only register, which is always read as all 1s.
Port Pull-Up Control Register 3 (PUCR3)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
— PUCR3₂ PUCR3₁ PUCR3₀
Initial value
0*
0*
0*
0*
0*
0
0
0
Read/Write
—
—
—
—
—
R/W
R/W
R/W
Note: * Bits 7 to 3 are reserved; they are always read as 0 and cannot be modified.
PUCR3 controls whether the MOS pull-up of each of the port 3 pins P3₂ to P3₀ 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.
Upon reset, PUCR3 is initialized to H'00.
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