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7.5.1.2
Generation
An interrupt request is generated from an external pin or peripheral function assigned as an interrupt
source or by setting the NVIC's Interrupt Set-Pending Register.
・ From external pin
Set the port control register so that the external pin can perform as an interrupt function pin.
・ From peripheral function
Set the peripheral function to make it possible to output interrupt requests.
See the chapter of each peripheral function for details.
・ By setting Interrupt Set-Pending Register (forced pending)
An interrupt request can be generated by setting the relevant bit of the Interrupt Set-Pend-
ing Register.
7.5.1.3
Transmission
An interrupt signal from an external pin or peripheral function is directly sent to the CPU unless it is
used to exit a standby mode.
Interrupt requests from interrupt sources that can be used for clearing a standby mode are transmitted
to the CPU via the clock generator. For these interrupt sources, appropriate settings must be made in the
clock generator in advance. External interrupt sources not used for exiting a standby mode can be used with-
out setting the clock generator.
7.5.1.4
Precautions when using external interrupt pins
If you use external interrupts, be aware the followings not to generate unexpected interrupts.
If input disabled (PxIE<PxmIE>="0"), inputs from external interrupt pins are "High". Also, if external in-
terrupts are not used as a trigger to release standby (route 6 of "Figure 7-1 Interrupt Route"), input sig-
nals from the external interrupt pins are directly sent to the CPU. Since the CPU recognizes "High" input
as an interrupt, interrupts occur if corresponding interrupts are enabled by the CPU as inputs are being dis-
abled.
To use the external interrupt without setting it as a standby trigger, set the interrupt pin input as "Low"
and enable it. Then, enable interrupts on the CPU.
Page 85
TMPM3V6/M3V4
2019-02-06
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