Datasheet

RL78/L12 CHAPTER 4 PORT FUNCTIONS

R01UH0330EJ0200 Rev.2.00 102

Dec 13, 2013

4.2.8 Port 12

P120 and P125 to P127 are 4-bit I/O ports with an output latch. These port pins can be set to the input mode or output

mode in 1-bit units using port mode register 12 (PM12). When used as an input port, use of an on-chip pull-up resistor

can be specified by pull-up resistor option register 12 (PU12).

P121 to P124 are 4-bit input-only ports.

Digital input/output or analog input can be specified for the P120 pin using port mode control register 12 (PMC12).

This port can also be used for A/D converter analog input, connecting resonator for main system clock, connecting

resonator for subsystem clock, external clock input for main system clock, external clock input for subsystem clock,

segment output of the LCD controller/driver, connecting the capacitor for the LCD controller/driver, and voltage pin for

driving the LCD.

Reset signal generation sets P120 to analog input, and sets P121 to P127 to input mode.

4.2.9 Port 13

P130 is a 1-bit output-only port with an output latch.

P137 is a 1-bit input-only port.

P130 is fixed an output port, and P137 is fixed an input port.

This port can also be used for external interrupt request input.

Remark When a reset takes effect, P130 outputs a low-level signal. If P130 is set to output a high-level signal before

a reset takes effect, the output signal of P130 can be dummy-output as the CPU reset signal.

P130

Set by software

Reset signal

4.2.10 Port 14

Port 14 is an I/O port with an output latch. Port 14 can be set to the input mode or output mode in 1-bit units using port

mode register 14 (PM14). When the P140 to P147 pins are used as an input port, use of an on-chip pull-up resistor can

be specified in 1-bit units by pull-up resistor option register 14 (PU14).

Digital input/output or analog input can be specified for the P142 to P145 pins using port mode control register 14

(PMC14).

This port can also be used for clock/buzzer output, segment output of the LCD controller/driver, A/D converter analog

input, and timer I/O.

Reset signal generation sets P140, P141, P146, and P147 to input mode, and sets P142 to P145 to analog input.

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