Renesas rl78 Answering Machine User Manual


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RL78/G1A CHAPTER 4 PORT FUNCTIONS
R01UH0305EJ0200 Rev.2.00 101
Jul 04, 2013
4.2.8 Port 7
Port 7 is an I/O port with an output latch. Port 7 can be set to the input mode or output mode in 1-bit units using port
mode register 7 (PM7). When 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 7 (PU7).
Output from the P71 and P74 pins can be specified as N-ch open-drain output (V
DD tolerance
Note 1
/EVDD tolerance
Note 2
) in
1-bit units using port output mode register 7 (POM7).
The P70 pin can be specified as digital input/output or analog input, using port mode control register 7 (PMC7).
This port can also be used for A/D converter analog input, key interrupt input, serial interface data I/O, clock I/O, and
external interrupt request input.
Reset signal generation sets port 7 to input mode.
Notes 1. For 25- to 48-pin products
2. For 64-pin products
4.2.9 Port 12
P120 is an I/O port 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 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.
The P120 pin can be specified as digital input/output or analog input, 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, and external clock input for subsystem clock.
Reset signal generation sets P120 to analog input, and sets P121 to P124 to input mode.
4.2.10 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 ports.
This port can also be used for external interrupt request input.
Remark When reset is effected, P130 outputs a low level. If P130 is set to output a high level before reset is effected,
the output signal of P130 can be dummy-output as the CPU reset signal.
P130
Set by software
Reset signal
<R>
<R>