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GD32E23x User Manual
106
5.4.
External interrupt and event (EXTI) block diagram
Figure 5-1. Block diagram of EXTI
EXTI Line0~27
Edge
detector
Polarity
Control
Software
Trigger
Interrupt Mask
Control
Event
Generate
Event Mask
Control
To NVIC
To Wakeup Unit
5.5.
External interrupt and Event function overview
The EXTI contains up to 21 independent edge detectors and generates interrupts request or
event to the processer. The EXTI has three trigger types: rising edge, falling edge and both
edges. Each edge detector in the EXTI can be configured and masked independently.
The EXTI trigger source includes 16 external lines from GPIO pins and 5 lines from internal
modules (
including LVD, RTC, USART and CMP
)
for GD32E23x
series.
All GPIO pins can be
selected as an EXTI trigger source by configuring SYSCFG_EXTISSx registers in SYSCFG
module (please refer to
System configuration registers (SYSCFG)
EXTI can provide not only interrupts but also event signals to the processor. The Cortex-M23
processor fully implements the Wait For Interrupt (WFI), Wait For Event (WFE) and the Send
Event (SEV) instructions. The Wake-up Interrupt Controller (WIC) enables the processor and
NVIC to be put into a very low-power sleep mode leaving the WIC to identify and prioritize
interrupts and event. EXTI can be used to wake up processor and the whole system when
some expected event occurs, such as a special GPIO pin toggling or RTC alarm.
Table 5-3. EXTI source
For GD32E230xx devices