Datasheet

4. When the transition counter meets the count threshold, the pin edge transition is validated and the
pin state PINSTATE.PINSTATE[x] is changed to the detected level.
5. The external interrupt flag (INTFLAG.EXTINT[x]) is set when the pin state PINSTATE.PINSTATE[x]
is changed.
Figure 23-3. EXTINT Pin Synchronous Debouncing (Rising Edge)
CLK_EIC
CLK_PRESCALER
EXTINTx
PIN_STATE
INTGLAG
TRANSITIONLOW
HIGH
Set INTFLAG
In the synchronous edge detection mode, the EIC clock is required. The synchronous edge detection
mode can be used in Idle and Standby sleep modes.
Asynchronous edge detection In this mode, the external interrupt (EXTINT) pin directly drives an
asynchronous edges detector which triggers any rising or falling edge on the pin:
1. Any edge detected that indicates a transition from the current valid pin state will immediately set the
valid pin state PINSTATE.PINSTATE[x] to the detected level.
2. The external interrupt flag (INTFLAG.EXTINT[x] is immediately changed.
3. The edge detector will then be idle until no other rising or falling edge transition is detected during 4
consecutive ticks of the low frequency clock.
4. Any rising or falling edge transition detected during the idle state will return the transition counter to
0.
5. After 4 consecutive ticks of the low frequency clock without bounce detected, the edge detector is
ready for a new detection.
Figure 23-4. EXTINT Pin Asynchronous Debouncing (Rising Edge)
CLK_EIC
CLK_PRESCALER
EXTINTx
PIN_STATE
INTGLAG
TRANSITION
LOW
HIGH
Set INTFLAG
In this mode, the EIC clock is requested. The asynchronous edge detection mode can be used in Idle and
Standby sleep modes.
23.6.5 DMA Operation
Not applicable.
23.6.6 Interrupts
The EIC has the following interrupt sources:
• External interrupt pins (EXTINTx). See 23.6.2 Basic Operation.
• Non-maskable interrupt pin (NMI). See 23.6.4 Additional Features.
SAM D5x/E5x Family Data Sheet
EIC – External Interrupt Controller
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 458