HD6433937 Datasheet, PDF (148/521 Pages) Hitachi Semiconductor – Hardware Manual

1. Port data register 1 (PDR1)
Bit
Initial value
Read/Write
7
P1 ₇
0
R/W
6
P1 ₆
0
R/W
5
P1 ₅
0
R/W
4
P1 ₄
0
R/W
3
P1 ₃
0
R/W
2
P1 ₂
0
R/W
1
P1 ₁
0
R/W
0
P1 ₀
0
R/W
PDR1 is an 8-bit register that stores data for port 1 pins P1₇ to P1₀. If port 1 is read while PCR1
bits are set to 1, the values stored in PDR1 are read, regardless of the actual pin states. If port 1 is
read while PCR1 bits are cleared to 0, the pin states are read.
Upon reset, PDR1 is initialized to H'00.
2. Port control register 1 (PCR1)
Bit
Initial value
Read/Write
7
PCR1₇
0
W
6
PCR1₆
0
W
5
PCR1₅
0
W
4
PCR1₄
0
W
3
PCR1₃
0
W
2
PCR1₂
0
W
1
PCR1₁
0
W
0
PCR1₀
0
W
PCR1 is an 8-bit register for controlling whether each of the port 1 pins P1₇ to P1₀ functions as an
input pin or output pin. Setting a PCR1 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 PCR1 and in PDR1 are valid only
when the corresponding pin is designated in PMR1 as a general I/O pin.
Upon reset, PCR1 is initialized to H'00.
PCR1 is a write-only register, which is always read as all 1s.
3. Port pull-up control register 1 (PUCR1)
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0
PUCR1₇ PUCR1₆ PUCR1₅ PUCR1₄ PUCR1₃ PUCR1₂ PUCR1₁ PUCR1₀
0
0
0
0
0
0
0
0
R/W
R/W R/W
R/W R/W R/W
R/W R/W
PUCR1 controls whether the MOS pull-up of each of the port 1 pins P1₇ to P1₀ is on or off. When
a PCR1 bit is cleared to 0, setting the corresponding PUCR1 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, PUCR1 is initialized to H'00.
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