Port Mode Register 2 (PMR2)
Bit
7
—
Initial value
1
Read/Write
—
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
/IRQ
3
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
PMOS Transistor Control (POF1)
5
This bit selects whether the PMOS transistor of the output buffer for pin P3
Bit 5
POF1
Description
0
CMOS output
1
NMOS open-drain output
Note: The pin is an NMOS open-drain output when this bit is set to 1 and P3
Rev. 6.00, 08/04, page 198 of 628
6
5
—
POF1
1
0
—
R/W
pin functions.
0
4
3
—
—
WDCKS
1
1
—
—
R/W
2
1
0
NCS
IRQ0
0
0
0
R/W
R/W
is on
5
is on or off.
5
(initial value)
is an output.
5
is
5