HD6432646 Hitachi, HD6432646 Datasheet - Page 278

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

Port 3 Register (PORT3)
Note: * Determined by the state of pins P37 to P30.
PORT3 is an 8-bit read-dedicated register, which reflects the state of pins. Write is disenabled.
Always carry out writing off output data of port 3 pins (P37 to P30) to P3DR without fail.
When P3DDR is set to 1, if port 3 is read, the values of P3DR are read. When P3DDR is cleared to
0, if port 3 is read, the states of pins are read out.
P3DDR and P3DR are initialized by a reset and in hardware standby mode, so PORT3 is
determined by the state of the pins. The previous state is maintained in software standby mode.
Port 3 Open Drain Control Register (P3ODR)
P3ODR is an 8-bit readable/writable register, which controls the on/off of port 3 pins (P37 to P30).
By setting P3ODR to 1, the port 3 pins become an open drain output, and when cleared to 0 they
become CMOS output.
P3ODR is initialized to H'00 by a reset and in hardware standby mode. The previous state is
maintained in software standby mode.
244
Bit
Initial value
Read/Write
Bit
Initial value
Read/Write
P37ODR
R/W
P37
—*
R
7
7
0
P36ODR
R/W
P36
—*
R
6
6
0
P35ODR
R/W
P35
—*
R
5
5
0
P34ODR
R/W
P34
—*
R
4
4
0
P33ODR
R/W
P33
—*
R
3
3
0
P32ODR
R/W
P32
—*
R
2
2
0
P31ODR
R/W
P31
—*
R
1
1
0
P30ODR
R/W
P30
—*
R
0
0
0