Exti Direct Event Input Wakeup; Exti Mux; Figure 28. Direct Event Trigger Logic Cpu Wakeup - ST STM32G0 1 Series Reference Manual

RM0444
Note: A detected configurable event interrupt pending request can be cleared by the CPU. The
system cannot enter low-power modes as long as an interrupt pending request is active.
13.3.2

EXTI direct event input wakeup

Figure 28
up the system.
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 wakeup event. The
peripheral synchronous interrupt, associated with the direct wakeup event wakes 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 interrupt flag of the associated peripheral is set.
AHB interface
hclk
hclk
Direct
Event
Asynchronous
input(x)
Rising Edge
detect circuit
rst
Falling Edge
detect
Pulse
generator
EXTI
13.3.3

EXTI mux

The EXTI mux allows selecting GPIOs as interrupts and wakeup. The GPIOs are connected
via 16 EXTI mux lines to the first 16 EXTI events as configurable event. The selection of
GPIO port as EXTI mux output is controlled through the
register (EXTI_EXTICRx)
is a detailed representation of the logic associated with direct event inputs waking

Figure 28. Direct event trigger logic CPU wakeup

Peripheral interface
CPU CPU
Interrupt Event
mask mask
register register
Other CPU Events(x,y)
CPU Wakeup(x)
Other CPU Wakeups
hclk
register.
Extended interrupt and event controller (EXTI)
Same circuit for Configurable
and Direct events
hclk
(1)
CPU Event(x)
Other Wakeups
Wakeup(x)
RM0444 Rev 5
EVG
c_evt_rst
Rising
Edge
c_evt_exti
detect
rst
hclk
c_wakeup
sys_wakeup
EXTI external interrupt selection
ck_fclk_c
CPU
c_event
Rising Edge
detect Pulse
generator
MS46536V1
321/1390
335