Hitachi H8/3937 Series Hardware Manual page 156

1. Port data register 2 (PDR2)
Bit 7
—
Initial value 0
Read/Write —
PDR2 is an 8-bit register that stores data for port 2 pins P2
bits are set to 1, the values stored in PDR2 are read directly. Do not read port 2 while PCR2 bits
are cleared to 0.
Upon reset, PDR2 is initialized to H'00.
2. Port control register 2 (PCR2)
Bit 7
—
Initial value 1
Read/Write —
PCR2 is an 8-bit register for controlling whether each of port 2 pins P2
input pin or output pin. Setting a PCR2 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 PCR2 and PDR2 are valid only
when the corresponding pin is designated in PMR2 as a general I/O pin.
Upon reset, PCR2 is initialized to H'00.
PCR2 is a write-only register, which is always read as all 1s.
3. Port mode register 2 (PMR2)
Bit 7
—
Initial value 1
Read/Write —
PMR2 is an 8-bit read/write register that controls the selection of pin functions for port 2 pins P2
P2 , and P2 , and the PMOS on/off state for the P2
1 2
Bit 5, the P2 /SO pin PMOS control bit (POF1), should be cleared to 0.
1
2
Upon reset, PMR2 is initialized to H'D8.
144
6 5 4
— — P2
0 0 0
— — R/W
6 5 4
— — PCR2
1 1 0
— — W
6 5 4
— POF1 —
1 0 1
— R/W —
/SO
2
3 2
P2 P2
4 3 2
0 0
R/W R/W
to P2 . If port 2 is read while PCR2
4 0
3 2
PCR2 PCR2
4 3
0 0
W W
to P2
4
3 2
— SO1
1 0
— R/W
pin.
1
1 0
P2 P2
1 0
0 0
R/W R/W
1 0
PCR2 PCR2
2 1 0
0 0
W W
functions as an
0
1 0
SI1 SCK1
0 0
R/W R/W
,
0