Renesas H8 Series - Page 246

Section 8 I/O Ports
Rev. 7.00 Mar 10, 2005 page 204 of 652
REJ09B0042-0700
Port Pull-Up Control Register 3 (PUCR3)
Bit
Initial value
Read/Write
7
PUCR3
0
R/W
6
PUCR3
0
R/W
5
PUCR3
0
R/W
4
PUCR3
0
R/W
3
PUCR3
0
R/W
0
PUCR3
0
0
R/W
2
PUCR3
0
R/W
1
PUCR3
0
R/W
2
1
5
4376
PUCR3 controls whether the MOS pull-up of each of the port 3 pins P3
7
to P3
0
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.
Port Mode Register 2 (PMR2)
Bit 76543210
— — POF1 — — WDCKS NCS IRQ0
Initial value 1 1 0 1 1 0 0 0
Read/Write — — R/W — — R/W R/W R/W
PMR2 is an 8-bit read/write register. It controls whether the PMOS transistor internal to P3
5
is on
or off, the selection of the watchdog timer clock, the selection of TMIG noise cancellation, and
switching of the P4
3
/ IRQ
0
pin functions.
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
5
is
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
5
PMOS Transistor Control (POF1)
This bit selects whether the PMOS transistor of the output buffer for pin P3
5
is on or off.
Bit 5
POF1 Description
0 CMOS output (initial value)
1 NMOS open-drain output
Note: The pin is an NMOS open-drain output when this bit is set to 1 and P3
5
is an output.