P20 To P25 (Port 2); P34 To P36 (Port 3) - NEC mPD780024AS Series Preliminary User's Manual

2.2.3 P20 to P25 (Port 2)

These are 6-bit I/O ports. Besides serving as I/O ports, they function as serial interface data I/O and clock I/O.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These ports function as 6-bit I/O ports. They can be specified as input or output ports in 1-bit units with port mode
register 2 (PM2). On-chip pull-up resistors can be used by setting pull-up resistor option register 2 (PU2).
(2) Control mode
These ports function as serial interface data I/O and clock I/O.
(a) SI30 and SO30
Serial interface serial data I/O pins.
(b) SCK30
Serial interface serial clock I/O pin.
(c) R D0 and T D0
X X
Asynchronous serial interface serial data I/O pins.
(d) ASCK0
Asynchronous serial interface serial clock input pin.

2.2.4 P34 to P36 (Port 3)

These are 3-bit I/O ports. Besides serving as I/O ports, they function as serial interface data I/O and clock I/O.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These ports function as 3-bit I/O ports. They can be specified as input or output ports in 1-bit units with port mode
register 3 (PM3). On-chip pull-up resistors can be used by setting pull-up resistor option register 3 (PU3).
(2) Control mode
These ports function as serial interface data I/O and clock I/O.
(a) SI31 and SO31
Serial interface serial data I/O pins.
(b) SCK31
Serial interface serial clock I/O pin.
CHAPTER 2 PIN FUNCTION
Preliminary User's Manual U16035EJ1V0UM
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