Exti Main Features; Exti Block Diagram; Wakeup Event Management; Figure 29. External Interrupt/Event Controller Block Diagram - ST STM32F423 Reference Manual

Interrupts and events
10.2.1

EXTI main features

The main features of the EXTI controller are the following:
•
independent trigger and mask on each interrupt/event line
•
dedicated status bit for each interrupt line
•
generation of up to 23 software event/interrupt requests
•
detection of external signals with a pulse width lower than the APB2 clock period. Refer
to the electrical characteristics section of the STM32F4xx datasheets for details on this
parameter.
10.2.2

EXTI block diagram

Figure 29
10.2.3

Wakeup event management

The STM32F4xx are able to handle external or internal events in order to wake up the core
(WFE). The wakeup event can be generated either by:
•
enabling an interrupt in the peripheral control register but not in the NVIC, and enabling
the SEVONPEND bit in the Cortex
MCU resumes from WFE, the peripheral interrupt pending bit and the peripheral NVIC
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shows the block diagram.

Figure 29. External interrupt/event controller block diagram

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