STM32 第17章 EXIT--外部中断/事件控制器

时间：2024.10.23

参考资料：《零死角玩转STM32》“EXTI-外部中断/事件控制器”

STM32里每一个GPIO都能产生中断，中断的产生体现在GPIO的电平的变化，电平的变化需要一个外设来管理，最终传给NVIC(内核里的嵌套中断控制器)来处理。

一、学习内容

1、EXTI功能框图+EXTI初始化结构体

1.1EXTI简介

EXTI:

External interrupt/event controller,外部中断/事件控制器

管理控制器的20个中断/事件线。每个中断/事件线都对应一个边沿检测器，可以实现输入信号的上升沿或下降沿的检测。EXTI可以实现对每个中断/事件线进行单独配置，可以单独配置为中断或者事件，以及触发事件的属性。

EXTI两大功能：

产生中断；产生事件

1.2EXIT功能框图

1.2.1输入线

1.输入线总共有多少，具体是哪一些?

输入线一共20条（20个中断/事件输入线），这些输入线可以通过寄存器设置为任意一个GPIO，也可以是一些外设的事件。输入线一般是存在电平变化的信号。

EXTI0至EXTI15用于GPIO，通过编程控制可以实现任意一个GPIO作为EXTI的输入源。

EXTI19针对的是互联型的单片机，即105和107系列的，103系列的没有这个输入线。

2.通过配置哪个寄存器来选择?

参考手册-8.4.3-8.4.6外部中断配置寄存器1-4(AFIO_EXTICR1-4)

3.用函数如何选择具体的输入线?

stm32f10x_gpio.h里的对应功能的函数

void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource);

详细功能说明：

/*** @brief  Selects the GPIO pin used as EXTI Line.* @param  GPIO_PortSource: selects the GPIO port to be used as source for EXTI lines.*   This parameter can be GPIO_PortSourceGPIOx where x can be (A..G).* @param  GPIO_PinSource: specifies the EXTI line to be configured.*   This parameter can be GPIO_PinSourcex where x can be (0..15).* @retval None*/
void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource)
{uint32_t tmp = 0x00;/* Check the parameters */assert_param(IS_GPIO_EXTI_PORT_SOURCE(GPIO_PortSource));assert_param(IS_GPIO_PIN_SOURCE(GPIO_PinSource));tmp = ((uint32_t)0x0F) << (0x04 * (GPIO_PinSource & (uint8_t)0x03));AFIO->EXTICR[GPIO_PinSource >> 0x02] &= ~tmp;AFIO->EXTICR[GPIO_PinSource >> 0x02] |= (((uint32_t)GPIO_PortSource) << (0x04 * (GPIO_PinSource & (uint8_t)0x03)));
}

1.2.2EXTI初始化结构体EXTI_InitTypeDef

1.EXTI_Line：用于产生中断/事件线

2.EXTI_Mode:EXTI模式(中断/事件）

3.EXTI_Trigger:触发(上/下/上下）

4.EXTI_LineCmd:使能或者失能(IMR/EMR）

在stm32f10x_exti.h里找到结构体

/** * @brief  EXTI Init Structure definition  */typedef struct
{uint32_t EXTI_Line;               /*!< Specifies the EXTI lines to be enabled or disabled.This parameter can be any combination of @ref EXTI_Lines */EXTIMode_TypeDef EXTI_Mode;       /*!< Specifies the mode for the EXTI lines.This parameter can be a value of @ref EXTIMode_TypeDef */EXTITrigger_TypeDef EXTI_Trigger; /*!< Specifies the trigger signal active edge for the EXTI lines.This parameter can be a value of @ref EXTIMode_TypeDef */FunctionalState EXTI_LineCmd;     /*!< Specifies the new state of the selected EXTI lines.This parameter can be set either to ENABLE or DISABLE */ 
}EXTI_InitTypeDef;

1.EXTI_Line：用于产生中断/事件线


/** @defgroup EXTI_Exported_Constants* @{*//** @defgroup EXTI_Lines * @{*/#define EXTI_Line0       ((uint32_t)0x00001)  /*!< External interrupt line 0 */
#define EXTI_Line1       ((uint32_t)0x00002)  /*!< External interrupt line 1 */
#define EXTI_Line2       ((uint32_t)0x00004)  /*!< External interrupt line 2 */
#define EXTI_Line3       ((uint32_t)0x00008)  /*!< External interrupt line 3 */
#define EXTI_Line4       ((uint32_t)0x00010)  /*!< External interrupt line 4 */
#define EXTI_Line5       ((uint32_t)0x00020)  /*!< External interrupt line 5 */
#define EXTI_Line6       ((uint32_t)0x00040)  /*!< External interrupt line 6 */
#define EXTI_Line7       ((uint32_t)0x00080)  /*!< External interrupt line 7 */
#define EXTI_Line8       ((uint32_t)0x00100)  /*!< External interrupt line 8 */
#define EXTI_Line9       ((uint32_t)0x00200)  /*!< External interrupt line 9 */
#define EXTI_Line10      ((uint32_t)0x00400)  /*!< External interrupt line 10 */
#define EXTI_Line11      ((uint32_t)0x00800)  /*!< External interrupt line 11 */
#define EXTI_Line12      ((uint32_t)0x01000)  /*!< External interrupt line 12 */
#define EXTI_Line13      ((uint32_t)0x02000)  /*!< External interrupt line 13 */
#define EXTI_Line14      ((uint32_t)0x04000)  /*!< External interrupt line 14 */
#define EXTI_Line15      ((uint32_t)0x08000)  /*!< External interrupt line 15 */
#define EXTI_Line16      ((uint32_t)0x10000)  /*!< External interrupt line 16 Connected to the PVD Output */
#define EXTI_Line17      ((uint32_t)0x20000)  /*!< External interrupt line 17 Connected to the RTC Alarm event */
#define EXTI_Line18      ((uint32_t)0x40000)  /*!< External interrupt line 18 Connected to the USB Device/USB OTG FSWakeup from suspend event */                                    
#define EXTI_Line19      ((uint32_t)0x80000)  /*!< External interrupt line 19 Connected to the Ethernet Wakeup event */#define IS_EXTI_LINE(LINE) ((((LINE) & (uint32_t)0xFFF00000) == 0x00) && ((LINE) != (uint16_t)0x00))
#define IS_GET_EXTI_LINE(LINE) (((LINE) == EXTI_Line0) || ((LINE) == EXTI_Line1) || \((LINE) == EXTI_Line2) || ((LINE) == EXTI_Line3) || \((LINE) == EXTI_Line4) || ((LINE) == EXTI_Line5) || \((LINE) == EXTI_Line6) || ((LINE) == EXTI_Line7) || \((LINE) == EXTI_Line8) || ((LINE) == EXTI_Line9) || \((LINE) == EXTI_Line10) || ((LINE) == EXTI_Line11) || \((LINE) == EXTI_Line12) || ((LINE) == EXTI_Line13) || \((LINE) == EXTI_Line14) || ((LINE) == EXTI_Line15) || \((LINE) == EXTI_Line16) || ((LINE) == EXTI_Line17) || \((LINE) == EXTI_Line18) || ((LINE) == EXTI_Line19))/*** @}*//*** @}*//** @defgroup EXTI_Exported_Macros* @{*//*** @}*/

EXTI_Line初始化对应的是向下图的哪个位写1，而不是选择总线

2.EXTI_Mode:EXTI模式(中断/事件）

/** * @brief  EXTI mode enumeration  */typedef enum
{EXTI_Mode_Interrupt = 0x00,EXTI_Mode_Event = 0x04
}EXTIMode_TypeDef;#define IS_EXTI_MODE(MODE) (((MODE) == EXTI_Mode_Interrupt) || ((MODE) == EXTI_Mode_Event))

3.EXTI_Trigger:触发(上/下/上下）

/** * @brief  EXTI Trigger enumeration  */typedef enum
{EXTI_Trigger_Rising = 0x08,EXTI_Trigger_Falling = 0x0C,  EXTI_Trigger_Rising_Falling = 0x10
}EXTITrigger_TypeDef;#define IS_EXTI_TRIGGER(TRIGGER) (((TRIGGER) == EXTI_Trigger_Rising) || \((TRIGGER) == EXTI_Trigger_Falling) || \((TRIGGER) == EXTI_Trigger_Rising_Falling))