CHAPTER 2 PIN FUNCTIONS
User’s Manual U16899EJ2V0UD
38
2.2.3 P20 to P27 (port 2)
P20 to P27 function as an 8-bit input-only port. These pins also function as pins for A/D converter analog input.
The following operation modes can be specified in 1-bit units.
(1) Port
mode
P20 to P27 function as an 8-bit input-only port.
(2) Control
mode
P20 to P27 function as A/D converter analog input pins (ANI0 to ANI7). When using these pins as analog input
pins, see (5) ANI0/P20 to ANI7/P27 in 12.6 Cautions for A/D Converter.
2.2.4 P30 to P33 (port 3)
P30 to P33 function as a 4-bit I/O port. These pins also function as pins for external interrupt request input and
timer I/O.
The following operation modes can be specified in 1-bit units.
(1) Port
mode
P30 to P33 function as a 4-bit I/O port. P30 to P33 can be set to input or output in 1-bit units using port mode
register 3 (PM3). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 3 (PU3).
(2) Control
mode
P30 to P33 function as external interrupt request input pins and timer I/O pins.
(a) INTP1 to INTP4
These are the external interrupt request input pins for which the valid edge (rising edge, falling edge, or both
rising and falling edges) can be specified.
(b) TI51
This is an external count clock input pin to 8-bit timer/event counter 51.
(c) TO51
This is a timer output pin.
Caution In
the
µ
PD78F0138HD, be sure to pull the P31 pin down after reset to prevent malfunction.
Remark P31/INTP2 and P32/INTP3 of the
µ
PD78F0138HD can be used as on-chip debug mode setting pins
when the on-chip debug function is used. For details, refer to CHAPTER 27 ON-CHIP DEBUG
FUNCTION (
µ
PD78F0138HD ONLY).
2.2.5 P40 to P43 (port 4)
P40 to P43 function as a 4-bit I/O port. P40 to P43 can be set to input or output in 1-bit units using port mode
register 4 (PM4). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 4 (PU4).
2.2.6 P50 to P53 (port 5)
P50 to P53 function as a 4-bit I/O port. P50 to P53 can be set to input or output in 1-bit units using port mode
register 5 (PM5). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 5 (PU5).