P40 To P45 (Port 4); P121 To P123 (Port 12); P130 (Port 13); Reset - NEC 78K0S/KA1+ Preliminary User's Manual

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2.2.3 P40 to P45 (Port 4)

P40 to P45 constitute a 6-bit I/O port, port 4. In addition to I/O port pins, these pins also have functions to output a
timer signal, input external interrupt request signals, and input/output the data of the serial interface.
These pins can be set to the following operation modes in 1-bit units.
(1) Port mode
P40 and P45 function as a 6-bit I/O port. Each bit of this port can be set to the input or output mode by using
port mode register 4 (PM4). In addition, an on-chip pull-up resistor can be connected to the port by using pull-
up resistor option register 4 (PU4).
(2) Control mode
P40 and 45 function to output a signal from an internal timer, input external interrupt request signals, and
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input/output data of the serial interface.
(a) INTP1 and INTP3
These are external interrupt request input pins for which the valid edge (rising edge, falling edge, or both
rising and falling edges) can be specified.
(b) TOH1
This is the output pin of 8-bit timer H1.
(c) TxD6
This pin outputs serial data from the asynchronous serial interface.
(d) RxD6
This pin inputs serial data to the asynchronous serial interface.

2.2.4 P121 to P123 (Port 12)

P121 to P123 constitute a 3-bit I/O port, port 12.
Each bit of this port can be set to the input or output mode by using port mode register 12 (PM12). An on-chip pull-
up resistor can be connected to P123 by using pull-up resistor option register 12 (PU12).
P121 and P122 also function as the X1 and X2 pins, respectively.

2.2.5 P130 (Port 13)

This is a 1-bit output-only port.

2.2.6 RESET

This pin inputs an active-low system reset signal.

2.2.7 X1 and X2

These pins connect an oscillator to oscillate the X1 input clock.
Supply an external clock to X1.
2.2.8 AV
REF
This pin inputs a reference voltage to the internal A/D converter. When the A/D converter is not used, connect this
pin to V .
DD
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CHAPTER 2 PIN FUNCTIONS
Preliminary User's Manual U16898EJ1V0UD