
CHAPTER 2 PIN FUNCTIONS
User’s Manual U17260EJ6V0UD
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2.2.3 P20 to P27 (port 2)
P20 to P27 function as an 8-bit I/O 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 I/O port. P20 to P27 can be set to input or output port in 1-bit units using port
mode register 2 (PM2).
(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 13.6 Cautions for A/D Converter.
Caution
ANI0/P20 to ANI7/P27 are set in the analog input mode after release of reset.
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 port 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 and timer I/O.
(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 from 8-bit timer/event counter 51.
Cautions 1. In the product with an on-chip debug function (
PD78F0537D), be sure to pull the
P31/INTP2/OCD1A
Note pin down before a reset release, to prevent malfunction.
2. For products without an on-chip debug function and with the flash memory of 48 KB or
more (
PD78F0534, 78F0535, 78F0536, and 78F0537) and having a product rank of “I”,
“K”, or “E”, and for the product with an on-chip debug function (
PD78F0537D),
connect P31/INTP2/OCD1A
Note
as follows when writing the flash memory with a flash
memory programmer.
P31/INTP2/OCD1ANote: Connect to EVSS via a resistor (10 k: recommended).
The above connection is not necessary when writing the flash memory by means of self
programming.
Note OCD1A is provided to the
PD78F0537D only.