Description Of Pin Functions; P00 To P07 (Port 0); P10 To P14 (Port 1); P20 To P27 (Port 2) - NEC mPD780973 Series Preliminary User's Manual

2.2 Description of Pin Functions

2.2.1 P00 to P07 (Port 0)

These pins constitute an 8-bit input/output port. In addition, they are also used to input external interrupt request
signals.
The following operating modes can be specified bit-wise.
(1) Port mode
In this mode, P00 to P07 function as an 8-bit input/output port.
P00 to P07 can be specified as an input or output port bit-wise with port mode register 0 (PM0). When these
pins are used as an input port, an on-chip pull-up resistor can be used if so specified by the pull-up resistor option
register (PU0).
(2) Control mode
In this mode, P00 to P07 function as external interrupt input pins (INTP0 to INTP2) and external interrupt request
input pins with specifiable valid edges (rising edge, falling edge, both rising and falling edges).

2.2.2 P10 to P14 (Port 1)

These pins constitute a 5-bit input only port. In addition, they are also used to input A/D converter analog signals.
The following operating modes can be specified bit-wise.
(1) Port mode
In this mode, P10 to P14 function as a 5-bit input only port.
(2) Control mode
In this mode, P10 to P14 function as A/D converter analog input pins (ANI0 to ANI4).

2.2.3 P20 to P27 (Port 2)

These pins constitute an 8-bit output only port. In addition, they are also used as PWM output pins to control meters.
The following operating modes can be specified bit-wise.
(1) Port mode
In this mode, P20 to P27 function as an 8-bit output only port. They go into a high-impedance state when 1 is
set to port mode register 2 (PM2).
(2) Control mode
In this mode, P20 to P27 function as PWM output pins (SM11 to SM14 and SM21 to SM24) for meter control.
CHAPTER 2 PIN FUNCTION
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