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CHAPTER 4 PIN FUNCTION (
μ
PD780058Y Subseries)
4.2.2 P10 to P17 (Port 1)
This is an 8-bit input/output port. Besides serving as an input/output port, it functions as an A/D converter analog
input.
The following operating modes can be specified bit-wise.
(1) Port mode
This port functions as an 8-bit input/output port.
It can be specified bit-wise as an input or output port with a port mode register 1 (PM1). If used as an input
port, on-chip pull-up resistor can be used to this port by defining the pull-up resistor option register L (PUOL).
(2) Control mode
This port functions as A/D converter analog input pins (ANI0 to ANI7). The on-chip pull-up resistor is
automatically disabled when the pins specified for analog input.
4.2.3 P20 to P27 (Port 2)
This is an 8-bit input/output port. Besides serving as an input/output port, it functions as data input/output to/from
the serial interface, clock input/output, automatic transmit/receive busy input, and strobe output functions.
The following operating modes can be specified bit-wise.
(1) Port mode
This port functions as an 8-bit input/output port. It can be specified bit-wise as an input or output port with
port mode register 2 (PM2). When it is used as an input port, on-chip pull-up resistors can be used to them
by defining the pull-up resistor option register L (PUOL).
(2) Control mode
This port functions as serial interface data input/output, clock input/output, automatic transmit/receive busy
input, and strobe output functions.
(a) SI0, SI1, SO0, SO1, SB0, SB1, SDA0, SDA1
Serial data input/output pins of serial interface
(b) SCK0, SCK1, SCL
Serial clock input/output pins of serial interface
(c) BUSY
Automatic transmit/receive busy input pins of serial interface
(d) STB
Automatic transmit/receive strobe output pins of serial interface
(e) RxD1, TxD1
Serial interface serial data input/output pins of asynchronous serial interface
Caution
When this port is used as a serial interface pin, the I/O and output latches must be set
according to the function the user requires. For the setting, refer to Figure 17-4 Serial
Operation Mode Register 0 Format, Figure 18-3 Serial Operation Mode Register 1
Format, and Table 19-2 Serial Interface Channel 2 Operating Mode Settings.