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CHAPTER 2 PIN FUNCTIONS
User’s Manual U15017EJ2V0UD
(e) ASCK0
These are baud rate clock I/O pins of the asynchronous serial interface.
2.2.4 P40 to P47 (Port 4)
P40 to 47 constitute an 8-bit I/O port. These pins can be set in the input or output mode in 1-bit units using the
port 4 mode register (PM4). The on-chip pull-up resistor can be specified in 8-bit units using bit 4 (PUO4) of the pull-
up resistor option register (PUO) only when it is used as an input port.
This port can directly drive an LED.
2.2.5 P50 to P57 (Port 5)
P50 to P57 constitute an 8-bit I/O port. These pins function alternately as a data input/output for serial interface
2 and clock input/output.
The following operation modes can be specified in 1-bit units.
(1) Port mode
In this mode, port 6 functions as an 8-bit I/O port. The port 5 mode register (PM5) can specify whether the
port functions as an input or output port, in 1-bit units.
These pins are N-ch open-drain pins. Pull-up resistors can be specified for these pins in the mask ROM
versions in 1-bit units using a mask option. The
μ
PD78F4976A does not have pull-up resistors.
(2) Control mode
In this mode, port 5 is provided with functions such as data input/output for serial interface 2 and clock input/
output.
(a) SI2 and SO2
These pins function as serial data I/O pins for serial interface 2.
(b) SCK2
This pin functions as a serial clock I/O pin for serial interface 2.
2.2.6 P60 to P67 (Port 6)
P60 to P67 constitute an 8-bit I/O port. These pins function alternately as data input/output for serial interface 1,
clock input/output, timer input/output, and external interrupt request input.
The following operation modes can be specified in 1-bit units.
(1) Port mode
In this mode, port 6 functions as an 8-bit I/O port. The port 6 mode register (PM6) can specify whether the
port functions as an input or output port in 1-bit units.
Use of on-chip pull-up resistors can be specified in 8-bit units using bit 6 of the pull-up resistor option register
(PUO) only when port 6 is used as an input port.
(2) Control mode
In this mode, port 6 is provided with functions such as data input/output for serial interface 1, clock input/output,
timer input/output, timer capture trigger signal input, and external interrupt request input.
(a) SI1 and SO1
These pins function as serial data I/O pins for serial interface 1.