STMicroelectronics STM32WL5 Series User Manual

Extended interrupts and event controller (EXTI) RM0453
512/1450 RM0453 Rev 5
Note: A detected configurable event interrupt pending request may be cleared by the CPU. The
system is not able to enter into low-power modes as long as an interrupt pending request is
active.
16.4.2 EXTI direct event input wake-up
The extended interrupt/event block diagram for direct events is shown in Figure 56. The
direct events allow the wake-up of the system and of the CPU from Sleep and Stop modes.
The direct events do not have an associated EXTI interrupt. The EXTI only wakes up the
system and CPU sub-system clocks and may generate a CPU wake-up event. The
peripheral synchronous interrupt associated with the direct wake-up event, wake up the
CPU. The EXTI direct event is able to generate a CPU event. This CPU event wakes up the
CPU.
The CPU event may occur before the associated peripheral interrupt flag is set.
Figure 56. Direct event trigger logic CPU wake-up
16.5 EXTI functional behavior
The direct event inputs are enabled in the respective peripheral generating the wake-up
event. The configurable events are enabled by enabling at least one of the trigger edges.
Once an event input is enabled, the generation of a CPU wake-up is conditioned by the
CPU interrupt mask and the CPU event mask.
MSv60762V1
Peripheral interface
EVG
EXTI
Direct event
input(x)
Asynchronous
rising edge
detect circuit
Falling edge
detect pulse
generator
rst
Delay
hclk
CPUn
rising edge
detect pulse
generator
hclk
ck_fclk_cn
cn_event
cn_wakeup
sys_wakeupCPUn other wakeups
Other wakeups
CPUn event(x)
(1)
CPUn wakeup(x)
Wakeup(x)
Logic duplicated for each CPU
Synch
hclk
AHB
interface
CPUn
interrupt
mask register
cn_evt_exti
hclk
CPUn
other events(x,y)
Rising edge
detect
hclk
rst
cn_evt_rst
CPUn
event
mask register
1) Only for the input events supporting the CPUn rxrev generation cn_event.
Same circuit for configurable
and direct events
Table 95. Masking functionality
CPU interrupt enable
EXTI_CnIMRm.IMb
CPU event enable
EXTI_CnEMRm.EMb
Configurable
event inputs
EXTI_PRm.PIFb
it_exti_per(y)
(1)
CPUn event
CPUn
wake-up
0
0 No Masked Masked Masked
1 No Masked Yes Yes

STMicroelectronics STM32WL5 Series Specifications

General

Brand	STMicroelectronics
Model	STM32WL5 Series
Category	Microcontrollers
Language	English