ST STM32F40 Series User Manual

Interrupts and events RM0090
257/1422 Doc ID 018909 Rev 4
10.2.1 EXTI main features
The main features of the EXTI controller are the following:
● independent trigger and mask on each interrupt/event line
● dedicated status bit for each interrupt line
● generation of up to 23 software event/interrupt requests
● detection of external signals with a pulse width lower than the APB2 clock period. Refer
to the electrical characteristics section of the STM32F4xx datasheets for details on this
parameter.
10.2.2 EXTI block diagram
Figure 32 shows the block diagram.
Figure 32. External interrupt/event controller block diagram
10.2.3 Wakeup event management
The STM32F4xx are able to handle external or internal events in order to wake up the core
(WFE). The wakeup event can be generated either by:
● enabling an interrupt in the peripheral control register but not in the NVIC, and enabling
the SEVONPEND bit in the Cortex™-M4F System Control register. When the MCU
Peripheral interface
Edge detect
circuit
AMBA APB bus
PCLK2
23
23 23
2323
23
23
To NVIC interrupt
controller
Software
interrupt
event
Register
Rising
trigger
selection
regsiter
23
Event
mask
register
Pulse
generator
23
23
23
23
Input
line
Pending
request
register
23
ai15896b
Interrupt
mask
register
Falling
trigger
selection
regsiter

ST STM32F40 Series Specifications

General

Brand	ST
Model	STM32F40 Series
Category	Microcontrollers
Language	English