External Interrupt / Event Controller (Exti); Introduction; Features; Figure 23. Exti Block Diagram - Holtek HT32F50231 User Manual

32-Bit Arm ® Cortex ® -M0+ MCU
HT32F50231/HT32F50241
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.
EXTI_PCLK
Debounce
16
EXTI 0
DBnCNT[15:0]
DBnEN
16
∫
EXTI 15
Deglitch

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
Rev. 1.00
High or Low level
Rising or Falling
or Both Edges
Edge/Level Software
Control Activate
(SRCnTYPE[2:0]) (EXTInSC)
16
Edge/Level
16
Detection
16
16
Polarity
Detection
Polarity
Control
(EXTInWPOL)
High or Low level
149 of 486
Interrupt Enable bits
& Interrupt Flags
16
EXTI Interrupt
16
Control &
Status
Event Enable bits
& Event Flags
EXTI Event
16
Control &
Status
16
External I/O Interrupt
(To NVIC control unit)
External I/O Event
16
(To NVIC control unit)
(To clock control unit)
July 31, 2018