AT32UC3L064_1 ATMEL [ATMEL Corporation], AT32UC3L064_1 Datasheet - Page 296

• Manufacturer Part Number: AT32UC3L064_1
• Description: AVR32 32-bit Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

17.6.2
Figure 17-2. Timing Diagram, Synchronous Interrupts, High Level or Rising Edge
32099A–AVR32–06/09
EXTINTn/NMI
FILTER off
FILTER on
ISR.INTn:
ISR.INTn:
CLK_SYNC
Synchronization and Filtering of External Interrupts
Writing a one to the INTn bit in the Enable Register (EN) enables the external interrupt on pin
EXTINTn, while writing a one to INTn bit in the Disable Register (DIS) disables the external inter-
rupt. The Control Register (CTRL) can be read to check which interrupts are enabled. If a bit in
the CTRL register is set, but the corresponding bit in IMR is not set, an interrupt will not propa-
gate to the interrupt controller. However, the corresponding bit in ISR will be set, and
EIC_WAKE will be set. Note that an external interrupt should not be enabled before it has been
configured correctly.
If the CTRL.INTn bit is zero, the corresponding bit in ISR will always be zero. Disabling an exter-
nal interrupt by writing a one to the DIS.INTn bit will clear the corresponding bit in ISR.
Please refer to the Module Configuration section for the number of external interrupts.
In synchronous mode the pin value of the EXTINTn pin is synchronized to CLK_SYNC, so
spikes shorter than one CLK_SYNC cycle are not guaranteed to produce an interrupt. The syn-
chronization of the EXTINTn to CLK_SYNC will delay the propagation of the interrupt to the
interrupt controller by two cycles of CLK_SYNC, see
(FILTER off).
It is also possible to apply a filter on EXTINTn by writing a one to the INTn bit in the FILTER reg-
ister. This filter is a majority voter, if the condition for an interrupt is true for more than one of the
latest three cycles of CLK_SYNC the interrupt will be set. This will additionally delay the propa-
gation of the interrupt to the interrupt controller by one or two cycles of CLK_SYNC, see
17-2
and
Figure 17-3
for examples (FILTER on).
Figure 17-2
and
Figure 17-3
AT32UC3L
for examples
Figure
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