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10.3 Pin of External Interrupt Circuit 1
This section describes the pins associated with external interrupt circuit 1 and
illustrates a block diagram of circuitry terminating at the pins with reference to the
registers and external interrupt triggering.
s Pins Associated with External Interrupt Circuit 1
The pins associated with external interrupt circuit 1 are the P34/TO/INT10 to P36/INT12 pins.
r P34/TO/INT10 pin
This pin functions as a general-purpose I/O dedicated port and may also serve 8/16-bit capture
timer outputs (TO) and external interrupt inputs (hysteresis inputs) (INT10).
If the timer 1 control register (TCR0) disables 8/16-bit capture timer outputs and, by the port
data direction register (DDR3), the pin is set to function as an input port only. The pin can also
function as an external interrupt input pin (INT10). When external interrupt 1 control register 1
(EIC1) sets edge detection to OFF, however, no external interrupt requests are generated, and
when interrupt request outputs are disabled, no interrupt requests are output. The pin state can
be read directly from the port data register (PDR3) at any time.
r P35/INT11 and P36/INT12 pins
These pins function as a general-purpose I/O dedicated port (P35, P36) and may also serve
external interrupt inputs (hysteresis inputs) (INT11, INT12).
If, by the port data direction register (DDR3), these pins are set to function as an input port only,
they also function as external interrupt input pins (INT11, INT12). When external interrupt 1
control registers 1 and 2 (EIC1, EIC2) set edge detection to OFF, however, no external interrupt
requests are generated, and when interrupt request outputs are disabled, no interrupt requests
are output. The pin state can be read directly from the port data register (PDR3) at any time.
Table 10.3-1 "Pins Associated with External Interrupt Circuit 1" lists the pins associated with
external interrupt circuit 1.
Table 10.3-1 Pins Associated with External Interrupt Circuit 1
External interrupt pin
Use for external interrupt input
(interrupt request output enabled)
Use for input port only
(Interrupt request output or edge
detection disabled)
P34/TO/INT10
INT10 (EIC1:EIE0=1, DDR3:bit4=0,
TCR2:PEN=0)
P34(EIC1:EIE0=0 or SL01, SL00=00B)
P35/INT11
INT11 (EIC1:EIE1=1, DDR3:bit5=0)
P35(EIC1:EIE1=0 or SL11, SL10=00B)
P36/INT12
INT12 (EIC2:EIE2=1, DDR3:bit6=0)
P36(EIC2:EIE2=0 or SL21, SL20=00B)
INT10 to INT12: When a signal with an edge or edges corresponding to the selected edge polarity is input to
these pins, an interrupt corresponding to the pin is generated.