外部中断理论

Tutorial: 电子电路 Category: 嵌入式 Published: 2026-08-29 08:09:36 Views: 0 Likes: 0 Comments: 0

109.3.4外部中断理论

/* ==================== Core\Inc\main.h ==================== */
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.h
  * @brief          : Header for main.c file.
  *                   This file contains the common defines of the application.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __MAIN_H
#define __MAIN_H

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "stm32f1xx_hal.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */

/* USER CODE END ET */

/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */

/* USER CODE END EC */

/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */

/* USER CODE END EM */

/* Exported functions prototypes ---------------------------------------------*/
void Error_Handler(void);

/* USER CODE BEGIN EFP */

/* USER CODE END EFP */

/* Private defines -----------------------------------------------------------*/
#define EXIT_KEY1_Pin GPIO_PIN_3
#define EXIT_KEY1_GPIO_Port GPIOE
#define EXIT_KEY1_EXTI_IRQn EXTI3_IRQn
#define EXTI_KEY2_Pin GPIO_PIN_4
#define EXTI_KEY2_GPIO_Port GPIOE
#define EXTI_KEY2_EXTI_IRQn EXTI4_IRQn
#define LED1_Pin GPIO_PIN_5
#define LED1_GPIO_Port GPIOB
#define BEEP_Pin GPIO_PIN_8
#define BEEP_GPIO_Port GPIOB

/* USER CODE BEGIN Private defines */

/* USER CODE END Private defines */

#ifdef __cplusplus
}
#endif

#endif /* __MAIN_H */

/* ==================== Core\Inc\gpio.h ==================== */
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    gpio.h
  * @brief   This file contains all the function prototypes for
  *          the gpio.c file
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __GPIO_H__
#define __GPIO_H__

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* USER CODE BEGIN Private defines */

/* USER CODE END Private defines */

void MX_GPIO_Init(void);

/* USER CODE BEGIN Prototypes */

/* USER CODE END Prototypes */

#ifdef __cplusplus
}
#endif
#endif /*__ GPIO_H__ */


/* ==================== Core\Inc\stm32f1xx_it.h ==================== */
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    stm32f1xx_it.h
  * @brief   This file contains the headers of the interrupt handlers.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
 ******************************************************************************
  */
/* USER CODE END Header */

/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __STM32F1xx_IT_H
#define __STM32F1xx_IT_H

#ifdef __cplusplus
 extern "C" {
#endif

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */

/* USER CODE END ET */

/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */

/* USER CODE END EC */

/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */

/* USER CODE END EM */

/* Exported functions prototypes ---------------------------------------------*/
void NMI_Handler(void);
void HardFault_Handler(void);
void MemManage_Handler(void);
void BusFault_Handler(void);
void UsageFault_Handler(void);
void SVC_Handler(void);
void DebugMon_Handler(void);
void PendSV_Handler(void);
void SysTick_Handler(void);
void EXTI3_IRQHandler(void);
void EXTI4_IRQHandler(void);
/* USER CODE BEGIN EFP */

/* USER CODE END EFP */

#ifdef __cplusplus
}
#endif

#endif /* __STM32F1xx_IT_H */

/* ==================== Core\Src\main.c ==================== */
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
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();
  /* USER CODE BEGIN 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 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
	HAL_Delay(10);
	if(HAL_GPIO_ReadPin(EXIT_KEY1_GPIO_Port, EXIT_KEY1_Pin)==0)
	{
		HAL_GPIO_TogglePin(BEEP_GPIO_Port, BEEP_Pin);
	}
	if(HAL_GPIO_ReadPin(EXTI_KEY2_GPIO_Port, EXTI_KEY2_Pin)==0)
	{
		HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
	}
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  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 /* USE_FULL_ASSERT */

/* ==================== Core\Src\gpio.c ==================== */
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    gpio.c
  * @brief   This file provides code for the configuration
  *          of all used GPIO pins.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "gpio.h"

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/*----------------------------------------------------------------------------*/
/* Configure GPIO                                                             */
/*----------------------------------------------------------------------------*/
/* USER CODE BEGIN 1 */

/* USER CODE END 1 */

/** Configure pins as
        * Analog
        * Input
        * Output
        * EVENT_OUT
        * EXTI
*/
void MX_GPIO_Init(void)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOE_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LED1_GPIO_Port, LED1_Pin, GPIO_PIN_SET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(BEEP_GPIO_Port, BEEP_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pins : PEPin PEPin */
  GPIO_InitStruct.Pin = EXIT_KEY1_Pin|EXTI_KEY2_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);

  /*Configure GPIO pin : PtPin */
  GPIO_InitStruct.Pin = LED1_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(LED1_GPIO_Port, &GPIO_InitStruct);

  /*Configure GPIO pin : PtPin */
  GPIO_InitStruct.Pin = BEEP_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_PULLDOWN;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(BEEP_GPIO_Port, &GPIO_InitStruct);

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI3_IRQn, 5, 0);
  HAL_NVIC_EnableIRQ(EXTI3_IRQn);

  HAL_NVIC_SetPriority(EXTI4_IRQn, 7, 0);
  HAL_NVIC_EnableIRQ(EXTI4_IRQn);

}

/* USER CODE BEGIN 2 */

/* USER CODE END 2 */

/* ==================== Core\Src\stm32f1xx_it.c ==================== */
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    stm32f1xx_it.c
  * @brief   Interrupt Service Routines.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f1xx_it.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD */

/* USER CODE END TD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/* External variables --------------------------------------------------------*/

/* USER CODE BEGIN EV */

/* USER CODE END EV */

/******************************************************************************/
/*           Cortex-M3 Processor Interruption and Exception Handlers          */
/******************************************************************************/
/**
  * @brief This function handles Non maskable interrupt.
  */
void NMI_Handler(void)
{
  /* USER CODE BEGIN NonMaskableInt_IRQn 0 */

  /* USER CODE END NonMaskableInt_IRQn 0 */
  /* USER CODE BEGIN NonMaskableInt_IRQn 1 */
   while (1)
  {
  }
  /* USER CODE END NonMaskableInt_IRQn 1 */
}

/**
  * @brief This function handles Hard fault interrupt.
  */
void HardFault_Handler(void)
{
  /* USER CODE BEGIN HardFault_IRQn 0 */

  /* USER CODE END HardFault_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_HardFault_IRQn 0 */
    /* USER CODE END W1_HardFault_IRQn 0 */
  }
}

/**
  * @brief This function handles Memory management fault.
  */
void MemManage_Handler(void)
{
  /* USER CODE BEGIN MemoryManagement_IRQn 0 */

  /* USER CODE END MemoryManagement_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
    /* USER CODE END W1_MemoryManagement_IRQn 0 */
  }
}

/**
  * @brief This function handles Prefetch fault, memory access fault.
  */
void BusFault_Handler(void)
{
  /* USER CODE BEGIN BusFault_IRQn 0 */

  /* USER CODE END BusFault_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_BusFault_IRQn 0 */
    /* USER CODE END W1_BusFault_IRQn 0 */
  }
}

/**
  * @brief This function handles Undefined instruction or illegal state.
  */
void UsageFault_Handler(void)
{
  /* USER CODE BEGIN UsageFault_IRQn 0 */

  /* USER CODE END UsageFault_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_UsageFault_IRQn 0 */
    /* USER CODE END W1_UsageFault_IRQn 0 */
  }
}

/**
  * @brief This function handles System service call via SWI instruction.
  */
void SVC_Handler(void)
{
  /* USER CODE BEGIN SVCall_IRQn 0 */

  /* USER CODE END SVCall_IRQn 0 */
  /* USER CODE BEGIN SVCall_IRQn 1 */

  /* USER CODE END SVCall_IRQn 1 */
}

/**
  * @brief This function handles Debug monitor.
  */
void DebugMon_Handler(void)
{
  /* USER CODE BEGIN DebugMonitor_IRQn 0 */

  /* USER CODE END DebugMonitor_IRQn 0 */
  /* USER CODE BEGIN DebugMonitor_IRQn 1 */

  /* USER CODE END DebugMonitor_IRQn 1 */
}

/**
  * @brief This function handles Pendable request for system service.
  */
void PendSV_Handler(void)
{
  /* USER CODE BEGIN PendSV_IRQn 0 */

  /* USER CODE END PendSV_IRQn 0 */
  /* USER CODE BEGIN PendSV_IRQn 1 */

  /* USER CODE END PendSV_IRQn 1 */
}

/**
  * @brief This function handles System tick timer.
  */
void SysTick_Handler(void)
{
  /* USER CODE BEGIN SysTick_IRQn 0 */

  /* USER CODE END SysTick_IRQn 0 */
  HAL_IncTick();
  /* USER CODE BEGIN SysTick_IRQn 1 */

  /* USER CODE END SysTick_IRQn 1 */
}

/******************************************************************************/
/* STM32F1xx Peripheral Interrupt Handlers                                    */
/* Add here the Interrupt Handlers for the used peripherals.                  */
/* For the available peripheral interrupt handler names,                      */
/* please refer to the startup file (startup_stm32f1xx.s).                    */
/******************************************************************************/

/**
  * @brief This function handles EXTI line3 interrupt.
  */
void EXTI3_IRQHandler(void)
{
  /* USER CODE BEGIN EXTI3_IRQn 0 */

  /* USER CODE END EXTI3_IRQn 0 */
  HAL_GPIO_EXTI_IRQHandler(EXIT_KEY1_Pin);
  /* USER CODE BEGIN EXTI3_IRQn 1 */

  /* USER CODE END EXTI3_IRQn 1 */
}

/**
  * @brief This function handles EXTI line4 interrupt.
  */
void EXTI4_IRQHandler(void)
{
  /* USER CODE BEGIN EXTI4_IRQn 0 */

  /* USER CODE END EXTI4_IRQn 0 */
  HAL_GPIO_EXTI_IRQHandler(EXTI_KEY2_Pin);
  /* USER CODE BEGIN EXTI4_IRQn 1 */

  /* USER CODE END EXTI4_IRQn 1 */
}

/* USER CODE BEGIN 1 */

/* USER CODE END 1 */

/* ==================== Core\Startup\startup_stm32f103zetx.s ==================== */
/**
  *************** (C) COPYRIGHT 2017 STMicroelectronics ************************
  * @file      startup_stm32f103xe.s
  * @author    MCD Application Team
  * @brief     STM32F103xE Devices vector table for Atollic toolchain.
  *            This module performs:
  *                - Set the initial SP
  *                - Set the initial PC == Reset_Handler,
  *                - Set the vector table entries with the exceptions ISR address
  *                - Configure the clock system   
  *                - Configure external SRAM mounted on STM3210E-EVAL board
  *                  to be used as data memory (optional, to be enabled by user)
  *                - Branches to main in the C library (which eventually
  *                  calls main()).
  *            After Reset the Cortex-M3 processor is in Thread mode,
  *            priority is Privileged, and the Stack is set to Main.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2017-2021 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

  .syntax unified
  .cpu cortex-m3
  .fpu softvfp
  .thumb

.global g_pfnVectors
.global Default_Handler

/* start address for the initialization values of the .data section.
defined in linker script */
.word _sidata
/* start address for the .data section. defined in linker script */
.word _sdata
/* end address for the .data section. defined in linker script */
.word _edata
/* start address for the .bss section. defined in linker script */
.word _sbss
/* end address for the .bss section. defined in linker script */
.word _ebss

.equ  BootRAM,        0xF1E0F85F
/**
 * @brief  This is the code that gets called when the processor first
 *          starts execution following a reset event. Only the absolutely
 *          necessary set is performed, after which the application
 *          supplied main() routine is called.
 * @param  None
 * @retval : None
*/

  .section .text.Reset_Handler
  .weak Reset_Handler
  .type Reset_Handler, %function
Reset_Handler:

/* Call the clock system initialization function.*/
    bl  SystemInit

/* Copy the data segment initializers from flash to SRAM */
  ldr r0, =_sdata
  ldr r1, =_edata
  ldr r2, =_sidata
  movs r3, #0
  b LoopCopyDataInit

CopyDataInit:
  ldr r4, [r2, r3]
  str r4, [r0, r3]
  adds r3, r3, #4

LoopCopyDataInit:
  adds r4, r0, r3
  cmp r4, r1
  bcc CopyDataInit
  
/* Zero fill the bss segment. */
  ldr r2, =_sbss
  ldr r4, =_ebss
  movs r3, #0
  b LoopFillZerobss

FillZerobss:
  str  r3, [r2]
  adds r2, r2, #4

LoopFillZerobss:
  cmp r2, r4
  bcc FillZerobss

/* Call static constructors */
    bl __libc_init_array
/* Call the application's entry point.*/
  bl main
  bx lr
.size Reset_Handler, .-Reset_Handler

/**
 * @brief  This is the code that gets called when the processor receives an
 *         unexpected interrupt.  This simply enters an infinite loop, preserving
 *         the system state for examination by a debugger.
 *
 * @param  None
 * @retval : None
*/
    .section .text.Default_Handler,"ax",%progbits
Default_Handler:
Infinite_Loop:
  b Infinite_Loop
  .size Default_Handler, .-Default_Handler
/******************************************************************************
*
* The minimal vector table for a Cortex M3.  Note that the proper constructs
* must be placed on this to ensure that it ends up at physical address
* 0x0000.0000.
*
******************************************************************************/
  .section .isr_vector,"a",%progbits
  .type g_pfnVectors, %object
  .size g_pfnVectors, .-g_pfnVectors


g_pfnVectors:

  .word _estack
  .word Reset_Handler
  .word NMI_Handler
  .word HardFault_Handler
  .word MemManage_Handler
  .word BusFault_Handler
  .word UsageFault_Handler
  .word 0
  .word 0
  .word 0
  .word 0
  .word SVC_Handler
  .word DebugMon_Handler
  .word 0
  .word PendSV_Handler
  .word SysTick_Handler
  .word WWDG_IRQHandler
  .word PVD_IRQHandler
  .word TAMPER_IRQHandler
  .word RTC_IRQHandler
  .word FLASH_IRQHandler
  .word RCC_IRQHandler
  .word EXTI0_IRQHandler
  .word EXTI1_IRQHandler
  .word EXTI2_IRQHandler
  .word EXTI3_IRQHandler
  .word EXTI4_IRQHandler
  .word DMA1_Channel1_IRQHandler
  .word DMA1_Channel2_IRQHandler
  .word DMA1_Channel3_IRQHandler
  .word DMA1_Channel4_IRQHandler
  .word DMA1_Channel5_IRQHandler
  .word DMA1_Channel6_IRQHandler
  .word DMA1_Channel7_IRQHandler
  .word ADC1_2_IRQHandler
  .word USB_HP_CAN1_TX_IRQHandler
  .word USB_LP_CAN1_RX0_IRQHandler
  .word CAN1_RX1_IRQHandler
  .word CAN1_SCE_IRQHandler
  .word EXTI9_5_IRQHandler
  .word TIM1_BRK_IRQHandler
  .word TIM1_UP_IRQHandler
  .word TIM1_TRG_COM_IRQHandler
  .word TIM1_CC_IRQHandler
  .word TIM2_IRQHandler
  .word TIM3_IRQHandler
  .word TIM4_IRQHandler
  .word I2C1_EV_IRQHandler
  .word I2C1_ER_IRQHandler
  .word I2C2_EV_IRQHandler
  .word I2C2_ER_IRQHandler
  .word SPI1_IRQHandler
  .word SPI2_IRQHandler
  .word USART1_IRQHandler
  .word USART2_IRQHandler
  .word USART3_IRQHandler
  .word EXTI15_10_IRQHandler
  .word RTC_Alarm_IRQHandler
  .word USBWakeUp_IRQHandler
  .word TIM8_BRK_IRQHandler
  .word TIM8_UP_IRQHandler
  .word TIM8_TRG_COM_IRQHandler
  .word TIM8_CC_IRQHandler
  .word ADC3_IRQHandler
  .word FSMC_IRQHandler
  .word SDIO_IRQHandler
  .word TIM5_IRQHandler
  .word SPI3_IRQHandler
  .word UART4_IRQHandler
  .word UART5_IRQHandler
  .word TIM6_IRQHandler
  .word TIM7_IRQHandler
  .word DMA2_Channel1_IRQHandler
  .word DMA2_Channel2_IRQHandler
  .word DMA2_Channel3_IRQHandler
  .word DMA2_Channel4_5_IRQHandler
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word BootRAM       /* @0x1E0. This is for boot in RAM mode for
                         STM32F10x High Density devices. */

/*******************************************************************************
*
* Provide weak aliases for each Exception handler to the Default_Handler.
* As they are weak aliases, any function with the same name will override
* this definition.
*
*******************************************************************************/

  .weak NMI_Handler
  .thumb_set NMI_Handler,Default_Handler

  .weak HardFault_Handler
  .thumb_set HardFault_Handler,Default_Handler

  .weak MemManage_Handler
  .thumb_set MemManage_Handler,Default_Handler

  .weak BusFault_Handler
  .thumb_set BusFault_Handler,Default_Handler

  .weak UsageFault_Handler
  .thumb_set UsageFault_Handler,Default_Handler

  .weak SVC_Handler
  .thumb_set SVC_Handler,Default_Handler

  .weak DebugMon_Handler
  .thumb_set DebugMon_Handler,Default_Handler

  .weak PendSV_Handler
  .thumb_set PendSV_Handler,Default_Handler

  .weak SysTick_Handler
  .thumb_set SysTick_Handler,Default_Handler

  .weak WWDG_IRQHandler
  .thumb_set WWDG_IRQHandler,Default_Handler

  .weak PVD_IRQHandler
  .thumb_set PVD_IRQHandler,Default_Handler

  .weak TAMPER_IRQHandler
  .thumb_set TAMPER_IRQHandler,Default_Handler

  .weak RTC_IRQHandler
  .thumb_set RTC_IRQHandler,Default_Handler

  .weak FLASH_IRQHandler
  .thumb_set FLASH_IRQHandler,Default_Handler

  .weak RCC_IRQHandler
  .thumb_set RCC_IRQHandler,Default_Handler

  .weak EXTI0_IRQHandler
  .thumb_set EXTI0_IRQHandler,Default_Handler

  .weak EXTI1_IRQHandler
  .thumb_set EXTI1_IRQHandler,Default_Handler

  .weak EXTI2_IRQHandler
  .thumb_set EXTI2_IRQHandler,Default_Handler

  .weak EXTI3_IRQHandler
  .thumb_set EXTI3_IRQHandler,Default_Handler

  .weak EXTI4_IRQHandler
  .thumb_set EXTI4_IRQHandler,Default_Handler

  .weak DMA1_Channel1_IRQHandler
  .thumb_set DMA1_Channel1_IRQHandler,Default_Handler

  .weak DMA1_Channel2_IRQHandler
  .thumb_set DMA1_Channel2_IRQHandler,Default_Handler

  .weak DMA1_Channel3_IRQHandler
  .thumb_set DMA1_Channel3_IRQHandler,Default_Handler

  .weak DMA1_Channel4_IRQHandler
  .thumb_set DMA1_Channel4_IRQHandler,Default_Handler

  .weak DMA1_Channel5_IRQHandler
  .thumb_set DMA1_Channel5_IRQHandler,Default_Handler

  .weak DMA1_Channel6_IRQHandler
  .thumb_set DMA1_Channel6_IRQHandler,Default_Handler

  .weak DMA1_Channel7_IRQHandler
  .thumb_set DMA1_Channel7_IRQHandler,Default_Handler

  .weak ADC1_2_IRQHandler
  .thumb_set ADC1_2_IRQHandler,Default_Handler

  .weak USB_HP_CAN1_TX_IRQHandler
  .thumb_set USB_HP_CAN1_TX_IRQHandler,Default_Handler

  .weak USB_LP_CAN1_RX0_IRQHandler
  .thumb_set USB_LP_CAN1_RX0_IRQHandler,Default_Handler

  .weak CAN1_RX1_IRQHandler
  .thumb_set CAN1_RX1_IRQHandler,Default_Handler

  .weak CAN1_SCE_IRQHandler
  .thumb_set CAN1_SCE_IRQHandler,Default_Handler

  .weak EXTI9_5_IRQHandler
  .thumb_set EXTI9_5_IRQHandler,Default_Handler

  .weak TIM1_BRK_IRQHandler
  .thumb_set TIM1_BRK_IRQHandler,Default_Handler

  .weak TIM1_UP_IRQHandler
  .thumb_set TIM1_UP_IRQHandler,Default_Handler

  .weak TIM1_TRG_COM_IRQHandler
  .thumb_set TIM1_TRG_COM_IRQHandler,Default_Handler

  .weak TIM1_CC_IRQHandler
  .thumb_set TIM1_CC_IRQHandler,Default_Handler

  .weak TIM2_IRQHandler
  .thumb_set TIM2_IRQHandler,Default_Handler

  .weak TIM3_IRQHandler
  .thumb_set TIM3_IRQHandler,Default_Handler

  .weak TIM4_IRQHandler
  .thumb_set TIM4_IRQHandler,Default_Handler

  .weak I2C1_EV_IRQHandler
  .thumb_set I2C1_EV_IRQHandler,Default_Handler

  .weak I2C1_ER_IRQHandler
  .thumb_set I2C1_ER_IRQHandler,Default_Handler

  .weak I2C2_EV_IRQHandler
  .thumb_set I2C2_EV_IRQHandler,Default_Handler

  .weak I2C2_ER_IRQHandler
  .thumb_set I2C2_ER_IRQHandler,Default_Handler

  .weak SPI1_IRQHandler
  .thumb_set SPI1_IRQHandler,Default_Handler

  .weak SPI2_IRQHandler
  .thumb_set SPI2_IRQHandler,Default_Handler

  .weak USART1_IRQHandler
  .thumb_set USART1_IRQHandler,Default_Handler

  .weak USART2_IRQHandler
  .thumb_set USART2_IRQHandler,Default_Handler

  .weak USART3_IRQHandler
  .thumb_set USART3_IRQHandler,Default_Handler

  .weak EXTI15_10_IRQHandler
  .thumb_set EXTI15_10_IRQHandler,Default_Handler

  .weak RTC_Alarm_IRQHandler
  .thumb_set RTC_Alarm_IRQHandler,Default_Handler

  .weak USBWakeUp_IRQHandler
  .thumb_set USBWakeUp_IRQHandler,Default_Handler

  .weak TIM8_BRK_IRQHandler
  .thumb_set TIM8_BRK_IRQHandler,Default_Handler

  .weak TIM8_UP_IRQHandler
  .thumb_set TIM8_UP_IRQHandler,Default_Handler

  .weak TIM8_TRG_COM_IRQHandler
  .thumb_set TIM8_TRG_COM_IRQHandler,Default_Handler

  .weak TIM8_CC_IRQHandler
  .thumb_set TIM8_CC_IRQHandler,Default_Handler

  .weak ADC3_IRQHandler
  .thumb_set ADC3_IRQHandler,Default_Handler

  .weak FSMC_IRQHandler
  .thumb_set FSMC_IRQHandler,Default_Handler

  .weak SDIO_IRQHandler
  .thumb_set SDIO_IRQHandler,Default_Handler

  .weak TIM5_IRQHandler
  .thumb_set TIM5_IRQHandler,Default_Handler

  .weak SPI3_IRQHandler
  .thumb_set SPI3_IRQHandler,Default_Handler

  .weak UART4_IRQHandler
  .thumb_set UART4_IRQHandler,Default_Handler

  .weak UART5_IRQHandler
  .thumb_set UART5_IRQHandler,Default_Handler

  .weak TIM6_IRQHandler
  .thumb_set TIM6_IRQHandler,Default_Handler

  .weak TIM7_IRQHandler
  .thumb_set TIM7_IRQHandler,Default_Handler

  .weak DMA2_Channel1_IRQHandler
  .thumb_set DMA2_Channel1_IRQHandler,Default_Handler

  .weak DMA2_Channel2_IRQHandler
  .thumb_set DMA2_Channel2_IRQHandler,Default_Handler

  .weak DMA2_Channel3_IRQHandler
  .thumb_set DMA2_Channel3_IRQHandler,Default_Handler

  .weak DMA2_Channel4_5_IRQHandler
  .thumb_set DMA2_Channel4_5_IRQHandler,Default_Handler

一、中断向量表

中断向量表是一张“异常编号到处理函数地址”的查找表。Cortex-M3 不需要在所有函数中搜索名字；NVIC 确定异常号后，处理器按固定索引从向量表读取入口地址。

课程 CubeIDE 工程的启动文件 startup_stm32f103zetx.s 中：

g_pfnVectors:
  .word _estack
  .word Reset_Handler
  .word NMI_Handler
  .word HardFault_Handler
  ...
  .word SysTick_Handler
  ...
  .word EXTI3_IRQHandler
  .word EXTI4_IRQHandler

向量表第 0 项不是函数地址，而是初始主栈指针 MSP；第 1 项是 Reset_Handler。之后先排列内核异常，再排列外设 IRQ。向量表基址由 SCB->VTOR 指定，通常位于 Flash 起始区域；引导程序或操作系统也可以重定位它。

VTOR
 │
 ├─ [0] 初始 MSP
 ├─ [1] Reset_Handler
 ├─ [2] NMI_Handler
 ├─ [3] HardFault_Handler
 │   ...
 ├─ [16 + EXTI3_IRQn] EXTI3_IRQHandler
 └─ [16 + EXTI4_IRQn] EXTI4_IRQHandler

若 C 文件中没有提供强定义，启动文件中的弱别名通常会把该入口指向 Default_Handler 的死循环。中断一来程序就像“卡死”，实际是进入了默认处理函数。

1.1 汇编初始化代码

本工程 Reset_Handler 的实际顺序：

调用 SystemInit，建立早期系统时钟和向量表设置；
把 Flash 中的 .data 初值复制到 SRAM；
把 .bss 段清零；
调用 __libc_init_array，执行 C/C++ 运行库初始化和静态构造；
调用 main；
若 main 意外返回，则执行 bx lr，嵌入式 main 通常不应返回。

flowchart TD
    RESET[硬件复位] --> MSP[从向量0加载MSP]
    MSP --> PC[从向量1加载Reset_Handler]
    PC --> SYS[SystemInit]
    SYS --> DATA[复制.data到SRAM]
    DATA --> BSS[清零.bss]
    BSS --> LIBC[__libc_init_array]
    LIBC --> MAIN[main]

Keil/ARM 启动文件的写法可能调用 SystemInit 后跳入 __main，由 C 库完成数据段初始化并最终调用 main。不能把某一种工具链的启动流程原样套到所有工程，必须查看当前使用的启动文件。

二、单片机中断

8051 和 Cortex-M3 都使用中断，但能力不同：

对比项	经典 8051	STM32F103 Cortex-M3
外部中断入口	INT0/P3.2、INT1/P3.3 固定	GPIO 0～15 经 AFIO 选择到 EXTI
向量	固定地址入口	向量表保存完整处理函数地址
优先级	层级较少	NVIC 多级可编程优先级
嵌套	受芯片结构限制	高抢占级可硬件嵌套
现场保存	软件/编译器为主	异常入口硬件自动压栈基本现场

Cortex-M3 进入异常时，硬件自动压栈 R0、R1、R2、R3、R12、LR、PC、xPSR。编译器按 ISR 实际使用情况保存其他寄存器。异常返回使用特殊 EXC_RETURN 值恢复现场。

“单片机没有操作系统”不代表不存在并发。中断可以在主循环任意位置发生，高优先级中断还能嵌套到低优先级 ISR 中，因此共享数据仍要同步。

三、中断机制

3.1 什么是中断

中断机制包含三个层次：

中断源：按键边沿、定时器溢出、串口接收等
控制器：EXTI/DMA/USART 等外设状态与使能
NVIC：统一仲裁外设 IRQ 的使能、挂起、活动和优先级

以 PE3 为例：

PE3 下降沿
 → EXTI3.PR3=1
 → IMR3允许
 → NVIC将EXTI3设为pending
 → 优先级条件满足
 → Cortex-M3异常入口
 → EXTI3_IRQHandler
 → HAL清PR3并调用Callback
 → 异常返回

3.1.1 中断的分类

可从不同角度分类：

分类方式	类型	示例
是否可屏蔽	不可屏蔽/可屏蔽	NMI；普通外设 IRQ
来源	内核异常/外设中断	HardFault、SysTick；EXTI、USART
触发特征	边沿/电平/状态条件	EXTI 上升沿；串口 RXNE
产生方式	硬件/软件	引脚边沿；EXTI_SWIER、PendSV

HardFault、NMI 等系统异常与普通外设 IRQ 的优先级规则并不完全相同。这里的 EXTI3/4 属于可屏蔽外设中断。

3.1.2 中断的处理流程

NVIC 中一个 IRQ 可能处于：

状态	含义
Disabled	通道关闭，不会被 CPU 响应
Enabled	通道允许响应
Pending	已有请求等待处理
Active	ISR 正在执行
Active + Pending	执行期间又来了新的请求

响应中断要同时满足：外设产生请求、外设中断使能、NVIC 通道使能、未被全局屏蔽、优先级允许。低或同抢占优先级的中断在高优先级 ISR 执行期间不会丢失为“死锁”，它通常保持 pending，等当前 ISR 返回后再执行；是否丢事件还取决于外设标志能否累计。

3.2 中断处理程序要少用延时的原因

ISR 中长延时有四类问题：

CPU 被当前 ISR 占用，主循环和低优先级中断无法运行；
同优先级或更低优先级请求只能排队，实时性下降；
外设标志通常只是一位，多个同类事件可能合并，无法计数；
HAL_Delay 依赖 SysTick；若 SysTick 不能抢占当前 ISR，延时可能永远等不到 tick 变化。

错误链：
EXTI ISR
  └─ HAL_Delay(10)
       └─ 等待 uwTick 增加
            └─ SysTick 优先级更低，无法进入
                 └─ EXTI ISR 无法结束

可靠做法是 ISR 记录标志和时间戳：

volatile uint16_t key_event_mask;

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
    key_event_mask |= GPIO_Pin;
}

主循环再根据 HAL_GetTick 做非阻塞消抖和设备控制。ISR 中“尽量短”不是追求形式，而是降低中断延迟、堆栈占用和共享状态复杂度。

四、外部通用中断线

STM32F103 的 EXTI0～15 对应 GPIO 引脚编号，端口由 AFIO_EXTICR 选择：

EXTI3 可选 PA3/PB3/PC3/PD3/PE3/PF3/PG3 中的一路
EXTI4 可选 PA4/PB4/PC4/PD4/PE4/PF4/PG4 中的一路

内部线：

线	来源
16	PVD
17	RTC Alarm
18	USB Wakeup
19	仅互联型器件的 Ethernet Wakeup

EXTI5～9 和 EXTI10～15 各共享一个 NVIC 向量，不表示这些线在 EXTI 内共用同一个挂起位。每条线仍有独立的 IMR、RTSR、FTSR、SWIER、PR 位；共享的是进入 CPU 的 IRQHandler。

五、中断机制总结

排查外部中断可从信号链逐层进行：

万用表或调试器确认引脚确有 1→0/0→1 变化；
检查 GPIO 输入模式与上下拉；
检查 AFIO_EXTICR 是否选择正确端口；
检查 RTSR/FTSR、IMR 与 PR；
检查 NVIC ISER、优先级和 pending/active 状态；
检查启动文件向量名与 C 函数名；
检查 HAL 是否清除挂起并进入用户回调；
检查 ISR 是否被延时、死循环或阻塞 API 卡住。

中断的核心不是“写一个回调函数”，而是从物理电平、边沿检测、外设挂起、NVIC 仲裁、向量入口到现场恢复的一条完整硬件与软件链。

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