目录

一、STM32中断概述

二、外部中断控制器EXTI

三、按键中断

四、串口中断

一、STM32中断概述

       在处理器中，中断是一个过程，即CPU在正常执行程序的过程中，遇到外部/内部的紧急事件需要处理，暂时中止当前程序的执行，转而去为处理紧急的事件，待处理完毕后再返回被打断的程序处继续往下执行。中断在计算机多任务处理，尤其是即时系统中尤为重要。比如uCOS，FreeRTOS等。

        中断能提高CPU的效率，同时能对突发事件做出实时处理。实现程序的并行化，实现嵌入式系统进程之间的切换

 进入中断

处理器自动保存现场到堆栈里 {PC, xPSR, R0-R3, R12, LR} 一旦入栈结束，ISR便可开始执行 晚到的中断会重新取ISR地址，但无需再次保存现场

退出中断

中断前的现场被自动从堆栈中恢复 一旦出栈完成，继续执行被中断打断的指令 出栈的过程也可被打断，使得随时可以响应新的中断， 而不再进行 现场保存

 NVIC的主要功能

n  Cortex-M0处理器中，每一个外部中断都可以被使能或者禁止，并且可以被设置为挂起状态或者清除状态。处理器的中断可以电平的形式的，也可以是脉冲形式的，这样中断控制器就可以处理任何中断源

      Cortex-M0内核可以处理15个内部异常，和32个外部中断。

      STM32F051实际上只使用了6个内部异常和28个外部中断。

     当异常或中断发生时，处理器会把PC设置为一个特定地址，这一地址就称为异常向量。每一类异常源都对应一个特定的入口地址，这些地址按照优先级排列以后就组成一张异常向量表。

向量化处理中断的好处

   统的处理方式需要软件去完成。采用向量表处理异常，M0处理器会从存储器的向量表中，自动定位异常的程序入口。从发生异常到异常的处理中间的时间被缩减。

注：中断和异常的区别：

       中断是微处理器外部发送的，通过中断通道送入处理器内部，一般是硬件引起的，比如串口接收中断，而异常通常是微处理器内部发生的，大多是软件引起的，比如除法出错异常，特权调用异常等待。不管是中断还是异常，微处理器通常都有相应的中断/异常服务程序

Ø 3个固定的优先级，都是负值，不能改变 Ø 四个可编程优先级，用两个bit位表示，00，01，10，11 Ø 优先级越小优先级越高

注：不同优先级的中断同时发生，优先处理优先级编号较小的那个

同样优先级的中断同时发生，中断向量号较小的那个优先响应

二、外部中断控制器EXTI

该器件具有一组配置寄存器。系统配置控制器的主要用途如下：

● 在部分 IO 口上启用或禁用 I2C 超快模式 (Fast Mode Plus) 。

● 重映射部分从 TIM16 和 TIM17 ， USART1 和 ADC 的 DMA 触发源到其它

   不同的 DMA 通道上。

● 重映射存储器到代码起始区域。

● 管理连接到 GPIO 口的外部中断。

● 管理系统的可靠性特性。

  系统配置控制器 (SYSCFG)

三、按键中断

Ø 1、使能相应的时钟 Ø2、配置GPIO管脚为中断功能 Ø3、设置中断优先级 Ø4、使能相应的中断 Ø5、实现中断服务程序

__weak表明他是一个若函数可以重写

/* USER CODE BEGIN 2 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{if(GPIO_Pin == GPIO_PIN_8){HAL_UART_Transmit(&huart1, "key int\n", 8, 100);}
}

 这是一个处理中断的回调函数，在里面判断一下是不是GPIO8，然后进行处理

中断优先级和触发方式都可以图形化配置

四、串口中断

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{if(huart->Instance == USART1){printf("uart tx end\n");}
}extern uint8_t RX[10] ;
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{if(huart->Instance == USART1){printf("REV : %x  %x\n",RX[0],RX[1]);HAL_UART_Receive_IT(&huart1, RX, 2);}
}

/********************************************************************************* File Name          : main.c* Description        : Main program body******************************************************************************** This notice applies to any and all portions of this file* that are not between comment pairs USER CODE BEGIN and* USER CODE END. Other portions of this file, whether * inserted by the user or by software development tools* are owned by their respective copyright owners.** COPYRIGHT(c) 2017 STMicroelectronics** Redistribution and use in source and binary forms, with or without modification,* are permitted provided that the following conditions are met:*   1. Redistributions of source code must retain the above copyright notice,*      this list of conditions and the following disclaimer.*   2. Redistributions in binary form must reproduce the above copyright notice,*      this list of conditions and the following disclaimer in the documentation*      and/or other materials provided with the distribution.*   3. Neither the name of STMicroelectronics nor the names of its contributors*      may be used to endorse or promote products derived from this software*      without specific prior written permission.** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.********************************************************************************/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f0xx_hal.h"
#include "usart.h"
#include "gpio.h"/* USER CODE BEGIN Includes *//* USER CODE END Includes *//* Private variables ---------------------------------------------------------*//* USER CODE BEGIN PV */uint8_t RX[10] = {0};/* Private variables ---------------------------------------------------------*//* USER CODE END PV *//* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*//* USER CODE END PFP *//* USER CODE BEGIN 0 */
int fputc(int ch, FILE *f)
{while(!(USART1->ISR & (1<<7)));USART1->TDR =ch;return ch;
}
/* USER CODE END 0 */int main(void)
{/* USER CODE BEGIN 1 *//* USER CODE END 1 *//* MCU Configuration----------------------------------------------------------*//* Reset of all peripherals, Initializes the Flash interface and the Systick. */HAL_Init();/* USER CODE BEGIN Init *//* USER CODE END Init *//* Configure the system clock */SystemClock_Config();/* USER CODE BEGIN SysInit *//* USER CODE END SysInit *//* Initialize all configured peripherals */MX_GPIO_Init();MX_USART1_UART_Init();/* USER CODE BEGIN 2 */HAL_UART_Transmit_IT(&huart1,"TX INT\n", 7);HAL_UART_Receive_IT(&huart1, RX, 2);/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){/* USER CODE END WHILE *//* USER CODE BEGIN 3 */}/* USER CODE END 3 */}/** System Clock Configuration
*/
void SystemClock_Config(void)
{RCC_OscInitTypeDef RCC_OscInitStruct;RCC_ClkInitTypeDef RCC_ClkInitStruct;RCC_PeriphCLKInitTypeDef PeriphClkInit;/**Initializes the CPU, AHB and APB busses clocks */RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;RCC_OscInitStruct.HSIState = RCC_HSI_ON;RCC_OscInitStruct.HSICalibrationValue = 16;RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK){_Error_Handler(__FILE__, __LINE__);}/**Initializes the CPU, AHB and APB busses clocks */RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1;RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK){_Error_Handler(__FILE__, __LINE__);}PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1;PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK1;if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK){_Error_Handler(__FILE__, __LINE__);}/**Configure the Systick interrupt time */HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);/**Configure the Systick */HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);/* SysTick_IRQn interrupt configuration */HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}/* USER CODE BEGIN 4 *//* USER CODE END 4 *//*** @brief  This function is executed in case of error occurrence.* @param  None* @retval None*/
void _Error_Handler(char * file, int line)
{/* USER CODE BEGIN Error_Handler_Debug *//* User can add his own implementation to report the HAL error return state */while(1) {}/* USER CODE END Error_Handler_Debug */ 
}#ifdef USE_FULL_ASSERT/*** @brief Reports the name of the source file and the source line number* where the assert_param error has occurred.* @param file: pointer to the source file name* @param line: assert_param error line source number* @retval None*/
void assert_failed(uint8_t* file, uint32_t line)
{/* USER CODE BEGIN 6 *//* User can add his own implementation to report the file name and line number,ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) *//* USER CODE END 6 */}#endif/*** @}*/ /*** @}
*/ /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/