Test STM32F4 Evnetout

See a lot of pins can be configured as Eventout, just have a pin to output a high-level pulse, tested a bit:

Environment: stm32f407, IAR 7.4, STM32CUBEF4

Gpio Configuration Code:

Gpio_initstruct.pin = gpio_pin_10;

Gpio_initstruct.mode = gpio_mode_af_pp;

Gpio_initstruct.pull = Gpio_pulldown;

Gpio_initstruct.speed = Gpio_speed_high;

Gpio_initstruct.alternate = Gpio_af15_eventout;

Hal_gpio_init (Gpiob, &gpio_initstruct);

Pulse output is a function defined in Intrinsics.h:

__setv ();

Output waveform:

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Oscilloscope sampling rate only in this way, an estimated 1 clocks, 1/168m=6ns.

Eventout uses according to data is used for synchronization between multiple arm. In comparison with the Gpio output, the Gpio outputs a pulse at least 3 instructions, and the access bus has a delay. and the output eventout only with one SEV instruction, the pulse is controlled directly by the kernel, the delay is minimal. However, this pulse is too narrow to meet the width of my application requirements, only the use of Gpio.

The receive event has not been tested, but the pin mode in the code can be set to:

#define Gpio_mode_evt_rising ((uint32_t) 0x10120000)/*!< External Event MODE with RISING Edge trig GER Detection */

#define Gpio_mode_evt_falling ((uint32_t) 0x10220000)/*!< External Event MODE with falling edge Tri Gger Detection */

#define Gpio_mode_evt_rising_falling ((uint32_t) 0x10320000)/*!< External Event MODE with rising/falling E DGE Trigger Detection * *

The receiver does not treat the event as an interrupt, but rather as a wake-up signal. Reference pm0214:stm32f3 and STM32F4 Series CORTEX-M4 programming Manual 2.5.1 Entering sleep mode.

This article is from the "Skywolf blog" blog, make sure to keep this source http://iskywolf.blog.51cto.com/5231583/1678934

Test STM32F4 Evnetout