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Rev. 1.00
179 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
11 External Interrupt/Event Controller (EXTI)
11 External Interrupt/Event Controller (EXTI)
Functional Descriptions
Wakeup Event Management
In order to wake up the system from the power saving mode, the EXTI controller provides a
function which can monitor external events and send them to the MCU core and the Clock Control
Unit, CKCU. These external events include EXTI events, Low Voltage Detection, WAKEUPn
input pin, Comparator and RTC wakeup functions. By configuring the wakeup event enable bit in
the corresponding peripheral, the wakeup signal will be sent to the MCU core and the CKCU via
the EXTI controller when the corresponding wakeup event occurs. Additionally, the software can
enable the event wakeup interrupt function by setting the EVWUPIEN bit in the EXTIWAKUPCR
register and the EXTI controller will then assert an interrupt when the wakeup event occurs.
Set event signal to
NVIC to wake up MCU
SLEEPING
(NVIC)
EXTI Wakeup Event Management
EXTInWFL
RTC_WAKEUP
LVD_WAKEUP
WUPF
PWRCU
EXTInWEN
High/Low
level detector
EXTInWPOL
1
0
16
16
16
16
16
16
RTC
16
16
16
CMP_WAKEUP
CMP
(Note)
16
EXTIn
WAKEUP1
HSI / HSE / PLL
WAKEUP
CKCU
OV / CM /
CSECWEN
LVDEWEN
WUP0EN
CMPWPEN
BOD_WAKEUP
BODEN
WAKEUP0
WUP1EN
Note: CMP is only available for the HT32F54243/HT32F54253 devices.
Figure 27. EXTI Wakeup Event Management
External Interrupt/Event Line Mapping
All GPIO pins can be selected as EXTI trigger sources by configuring the EXTInPIN[3:0] field in
the AFIO ESSRn (n = 0 ~ 1) register to trigger an interrupt or event. Refer to the AFIO section for
more details.