CHAPTER 2 PIN FUNCTIONS
User’s Manual U12697EJ3V0UM
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(i)
SI2, SO2
These are the I/O pins for serial data in the serial interface.
(ii)
SCK2
This is the I/O pin of the serial clock in the serial interface.
(iii) RxD2, TxD2
These are the serial data I/O pins in the asynchronous serial interface.
(iv) ASCK2
This is the baud rate clock input pin in the asynchronous serial interface.
(9) P120 to P127 (Port 12)
These pins constitute an 8-bit I/O port. In addition to I/O port pins, they also function as a real-time output port.
The following operation modes can be specified in 1-bit units.
(a) Port mode
These pins function as an 8-bit I/O port. Input or output can be specified in 1-bit units by means of the port
12 mode register. Regardless of whether the input mode or output mode is specified, pull-up resistors can
be connected in 1-bit units using pull-up resistor option register 12.
(b) Control mode
These pins function as a real-time output port (RTP0 to RTP7) that outputs data synchronized with a trigger.
When the pins specified as the real-time output port are read, 0 is read.
(10) P130, P131 (Port 13)
These pins constitute a 2-bit I/O port. In addition to I/O port pins, they also function as the analog outputs of
the D/A converter.
The following operation modes can be specified in 2-bit units.
(a) Port mode
These pins function as a 2-bit I/O port. Input or output can be specified in 1-bit units by means of the port
13 mode register. On-chip pull-up resistors are not available.
(b) Control mode
These pins function as the analog outputs (ANO0, ANO1) of the D/A converter. The values are undefined
when the pins specified as analog outputs are read.
Caution If the D/A converter uses only one channel when AV
REF1
< V
DD
, use either of the following
processes at pins that are not used for analog output.
•
Set the port mode register (PM13X) to 1 (input mode) and connect to V
SS0
.
•
Set the port mode register (PM13X) to 0 (output mode). Set the output latch to 0 and
output a low level.
