RL78/F13, F14 CHAPTER 4 PORT FUNCTIONS
R01UH0368EJ0210 Rev.2.10 288
Dec 10, 2015
4.2.11 Port 12
P120 and P125 to P127 are I/O ports with an output latch. Port 12 can be set to the input mode or output mode in 1-bit
units using port mode register 12 (PM12). When the P120 and P125 to P127 pins are used as an input port, use of an on-
chip pull-up resistor can be specified by pull-up resistor option register 12 (PU12).
Input to the P125 pin can be specified through a normal input buffer or a TTL input buffer in 1-bit units using port input
mode register 12 (PIM12). For the P125 pin input, the threshold of the input buffer can be specified in 1-bit units using the
port input threshold control register 12 (PITHL12).
Output from the P120 pin can be specified as N-ch open-drain output (EV
DD tolerance) in 1-bit units using port output
mode register 12 (POM12).
When P120 and P125 are used as input pins, specify analog input or digital input in 1-bit units using port mode control
register 12 (PMC12).
This port can also be used for A/D converter analog input, resonator connection for main system clock, resonator
connection for subsystem clock, external clock input for main system clock, external clock input for subsystem clock, timer
I/O, serial interface data output, slave select input, external interrupt request input, and SNOOZE status output.
Reset signal generation sets P120 and P125 to analog input mode and P121 to P124 to input mode.
Table 4-22. Settings of Registers When Using Port 12 (1/2)
Pin Name PM12x PIM12x POM12x PMC12x PITHL12x Alternate Function Setting
Note 5
Remark
Name I/O
P120 Input 1 – × 0 – ×
Output 0 – 0 0 – TRDIOD0 output = 0
Note 1
TO07 output = 0
Note 2
SO01 output = 1
Note 3
CMOS output
0 – 1 0 – N-ch O.D output
P121 Input – – – – – OSCSEL bit of CMC register = 0
or EXCLK bit = 1
P122 Input – – – – – OSCSEL bit of CMC register = 0
P123 Input – – – – –
OSCSELS bit of CMC register =
0
or EXCLKS bit = 1
or SELLOSC bit of CKSEL
register = 1
P124 Input – – – – –
OSCSELS bit of CMC register =
0
or SELLOSC bit of CKSEL
register = 1
P125 Input 1 0 – 0 0 × CMOS input
(Schmitt1 input)
1 CMOS input
(Schmitt3 input)
1 1 – 0 × × TTL input
Output 0 × – 0 × TRDIOB0 output = 0
Note 1
TO03 output = 0
Note 2
SNZOUT1 output = 0
Note 4
(Notes, Caution, and Remark are listed on the next page.)
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