UPD78F1502AGK-GAK-AX Datasheet, PDF (184/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 4 PORT FUNCTIONS
4.2.13 Port 12
<R>
P120/INTP0/EXLVI
P121/X1
P122/X2/EXCLK
P123/XT1
P124/XT2
78K0R/LF3
(80 pins: μ PD78F15x0A,
78F1501A, 78F15x2A)
78K0R/LG3
(100 pins: μ PD78F15x3A,
78F1504A, 78F15x5A)
√
√
√
√
√
78K0R/LH3
(128 pins: μ PD78F15x6A,
78F1507A, 78F15x8A)
P120 is a 1-bit 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 ports.
This port can also be used for external interrupt request input, potential input for external low-voltage detection,
connecting resonator for main system clock, connecting resonator for subsystem clock, and external clock input for main
system clock.
Reset signal generation sets port 12 to input mode.
Figures 4-29 to 4-31 show block diagrams of port 12.
Caution The function setting on P121 to P124 is available only once after the reset release. The port once set
for connection to an oscillator cannot be used as an input port unless the reset is performed.
R01UH0004EJ0501 Rev.5.01
168
Jun 20, 2011