hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 246

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

Section 8 I/O Ports
Port Pull-Up Control Register 3 (PUCR3)
PUCR3 controls whether the MOS pull-up of each of the port 3 pins P3
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.
Port Mode Register 2 (PMR2)
PMR2 is an 8-bit read/write register. It controls whether the PMOS transistor internal to P3
or off, the selection of the watchdog timer clock, the selection of TMIG noise cancellation, and
switching of the P4
Upon reset, PMR2 is initialized to H'D8.
This section only deals with the bit that controls whether the PMOS transistor internal to pin P3
on or off. For the functions of the other bits, see the descriptions of port 1 (WDCKS and NCS) and
port 4 (IRQ0).
Bit 5—Pin P3
This bit selects whether the PMOS transistor of the output buffer for pin P3
Bit 5
POF1
0
1
Note: The pin is an NMOS open-drain output when this bit is set to 1 and P3
Rev. 7.00 Mar 10, 2005 page 204 of 652
REJ09B0042-0700
Bit
Initial value
Read/Write
Bit
Initial value
Read/Write
5
Description
CMOS output
NMOS open-drain output
PMOS Transistor Control (POF1)
PUCR3
3
R/W
—
—
/
7
1
I R Q
7
0
7
0
pin functions.
PUCR3
R/W
—
—
6
1
6
0
6
PUCR3
POF1
R/W
R/W
5
0
5
0
5
PUCR3
R/W
—
4
0
—
4
1
4
PUCR3
R/W
3
0
—
—
3
1
3
PUCR3
WDCKS
R/W
R/W
2
0
7
2
0
to P3
2
5
is on or off.
5
PUCR3
0
is an output.
R/W
is on or off. When
1
0
NCS
R/W
1
0
1
(initial value)
PUCR3
R/W
0
0
IRQ0
5
R/W
is on
0
0
0
5
is