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CHAPTER 4 PIN FUNCTION (
μ
PD780024Y, 780034Y SUBSERIES)
4.2.3 P20 to P25 (Port 2)
These are 6-bit input/output ports. Besides serving as input/output ports, they function as data input/output to/from
the serial interface and clock input/output functions.
The following operating modes can be specified bit-wise.
(1) Port mode
These ports function as 6-bit input/output ports. They can be specified bit-wise as input or output ports with port
mode register 2 (PM2). When they are used as input ports, on-chip pull-up resistors can be used for them by
setting pull-up resistor option register 2 (PU2).
(2) Control mode
These ports function as serial interface data input/output and clock input/output.
(a) SI30 and SO30
Serial interface serial data input/output pins.
(b) SCK30
Serial interface serial clock input/output pin.
(c) R
X
D0, T
X
D0
Asynchronous serial interface serial data input/output pins.
(d) ASCK0
Asynchronous serial interface serial clock input pin.
4.2.4 P30 to P36 (Port 3)
These are 7-bit input/output ports. Beside serving as input/output ports, they function as serial interface data input/
output and clock input/output.
P30 to P33 (Port 3) can drive LEDs directly.
The following operating modes can be specified bit-wise.
(1) Port mode
These ports function as 7-bit input/output ports. They can be specified bit-wise as input or output ports with port
mode register 3 (PM3). P30 to P33 are N-ch open drain output. Mask ROM version can contain pull-up resistors
in P30 and P31 with the mask option. When P34 to P36 are used as input ports, on-chip pull-up resistors can
be used by defining the pull-up resistor option register 3 (PU3).
(2) Control mode
These ports function as serial interface serial data input/output and clock input/output.
(a) SDA0
Serial interface serial data input/output pin.
(b) SCL0
Serial interface serial clock input/output pin.