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Rev. 1.00
149 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
11 External Interrupt / Event Controller (EXTI)
11
External Interrupt / Event Controller (EXTI)
Introduction
The External Interrupt / Event Controller, EXTI, comprises 16 edge detectors which can generate
a wakeup event or interrupt requests independently. In the interrupt mode there are five trigger
types which can be selected as the external interrupt trigger type, low level, high level, negative
edge, positive edge and both edges, selectable using the SRCnTYPE field in the EXTICFGRn
(n = 0 ~ 15) register. In the wakeup event mode, the wakeup event polarity can be configured by
setting the EXTInWPOL (n = 0 ~ 15) field in the EXTIWAKUPPOLR register. If the EVWUPIEN
bit in the EXTIWAKUPCR Register is set, the EVWUP interrupt can be generated when the
associated wakeup event occurs and the corresponding EXTI wakeup enable bit is set. Each EXTI
line can also be masked independently.
Debounce
Deglitch
Edge/Level
Detection
Polarity
Detection
Polarity
Control
(EXTInWPOL)
Edge/Level
Control
(SRCnTYPE[2:0])
EXTI Interrupt
Control &
Status
EXTI Event
Control &
Status
Software
Activate
(EXTInSC)
EXTI 0
∫
EXTI 15
DBnCNT[15:0]
16
16
16
16
16
16
16
16
16
16
High or Low level
High or Low level
Rising or Falling
or Both Edges
Interrupt Enable bits
& Interrupt Flags
Event Enable bits
& Event Flags
External I/O Interrupt
(To NVIC control unit)
External I/O Event
(To NVIC control unit)
(To clock control unit)
DBnEN
16
EXTI_PCLK
Figure 23. EXTI Block Diagram
Features
▄
Up to 16 EXTI lines with configurable trigger source and type
●
All GPIO pins can be selected as EXTI trigger source
●
Source trigger type includes high level, low level, negative edge, positive edge or both edge
▄
Individual interrupt enable, wakeup enable and status bits for each EXTI line
▄
Software interrupt trigger mode for each EXTI line
▄
Integrated deglitch filter for short pulse blocking