Datasheet

Section 8 I/O Ports
Rev. 8.00 Mar. 09, 2010 Page 200 of 658
REJ09B0042-0800
Bit 4—P1
4
/IRQ
4
/ADTRG Pin Function Switch (IRQ4)
This bit selects whether pin P1
4
/IRQ
4
/ADTRG is used as P1
4
or as IRQ
4
/ADTRG.
Bit 4
IRQ4 Description
0 Functions as P1
4
I/O pin (initial value)
1 Functions as IRQ
4
/ADTRG input pin
Note: For details of ADTRG pin setting, see section 12.3.2, Start of A/D Conversion by External
Trigger Input.
Bit 3—P1
3
/TMIG Pin Function Switch (TMIG)
This bit selects whether pin P1
3
/TMIG is used as P1
3
or as TMIG.
Bit 3
TMIG Description
0 Functions as P1
3
I/O pin (initial value)
1 Functions as TMIG input pin
Bits 2 and 0—Reserved
These bits are reserved; they can only be written with 0.
Bit 1—Reserved
This bit is reserved; it is always read as 1 and cannot be modified.
Port Mode Register 2 (PMR2)
Bit 7 6 5 4 3 2 1 0
— — 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.