hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 252

• 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 Control Register 4 (PCR4)
PCR4 is an 8-bit register for controlling whether each of port 4 pins P4
input pin or output pin. Setting a PCR4 bit to 1 makes the corresponding pin an output pin, while
clearing the bit to 0 makes the pin an input pin. PCR4 and PDR4 settings are valid when the
corresponding pins are designated for general-purpose input/output by SCR3.
Upon reset, PCR4 is initialized to H'F8.
PCR4 is a write-only register, which is always read as all 1s.
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 switching of the P4
functions of the other bits, see the descriptions of port 1 (WDCKS and NCS) and port 3 (POF1).
Bit 0—P4
This bit selects whether pin P4
Bit 0
IRQ
0
1
Rev. 7.00 Mar 10, 2005 page 210 of 652
REJ09B0042-0700
Bit
Initial value
Read/Write
Bit
Initial value
Read/Write
0
3
/
I R Q
Description
Functions as P4
Functions as
0
Pin Function Switch (IRQ
3
/




I R Q
7
1
7
1
0
pin functions.
I R Q
3
3




6
1
6
1
0
/
input pin
I R Q
input pin
0
is used as P4
POF1
R/W


5
1
5
0
0
)




3
4
1
4
1
or as
I R Q




3
1
3
1
0
.
WDCKS
PCR4
3
/
R/W
I R Q
W
2
0
2
0
2
to P4
0
2
pin functions. For the
0
PCR4
functions as an
NCS
R/W
W
1
0
1
0
1
(initial value)
PCR4
IRQ
R/W
W
0
0
0
0
5
is on
0
0