GD32F403xx User Manual
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7.
Interrupt/event controller (EXTI)
7.1.
Overview
Cortex-M4 integrates the Nested Vectored Interrupt Controller (NVIC) f or efficient exception
and interrupts processing. NVIC f acilitates low-latency exception and interrupt handling and
controls power management. It’s tightly coupled to the processer core. More details about
NVIC could referred to the technical reference manual of cortex-M4.
EXTI (interrupt/event controller) contains up to 19 independent edge detectors and generates
interrupt requests or events to the processer. The EXTI has three trigger types: rising edge,
f alling edge and both edges. Each edge detector in the EXTI can be configured and masked
independently.
7.2.
Characteristics
◼
Cortex-M4 system exception.
◼
Up to 68 maskable peripheral interrupts.
◼
4 bits interrupt priority configuration
—16 priority levels.
◼
Ef ficient interrupt processing.
◼
Support exception pre-emption and tail-chaining.
◼
Wake up system from power saving mode.
◼
Up to 19 independent edge detectors in EXTI.
◼
Three trigger types: rising, falling and both edges.
◼
Sof tware interrupt or event trigger.
◼
Trigger sources configurable.
7.3.
Interrupts function overview
The Arm
®
Cortex
®
-M4 processor and the Nested Vectored Interrupt Controller (NVIC)
prioritize and handle all exceptions in Handler Mode. The processor state is automatically
stored to the stack on an exception and automatically restored f rom the stack at the end of
the Interrupt Service Routine (ISR).
The vector is f etched in parallel to the state saving, enabling efficient interrupt entry. The
processor supports tail-chaining, which enables back-to-back interrupts to be performed
without the overhead of state saving and restoration. The f ollowing tables list all exc eption
types.