Arm Systick定时器中断不'；t工作在TM4C123上

我是新来的，希望能得到帮助

我的问题是关于tm4c123gh6pm m4处理器上的systick中断。当我使用systick作为计时器（禁用中断）时，它工作正常，但当我启用中断时，当systick计数器达到值0时，它将触发中断，它将转到

IntDefaultHandler（void）

文件中的

startup.c

中。我甚至不启用全局中断。但是当我启用全局中断时，我得到了相同的结果。我正在分享下面的代码，请注意注释行。顺便说一下，我使用iar作为编译器

#include <stdint.h>
#include <stdio.h>
#include "inc/tm4c123gh6pm.h"

volatile unsigned long Counts=0; 

void SysTick_Init(unsigned long period){ // priority 2
  NVIC_ST_CTRL_R = 0;         // disable SysTick during setup
  NVIC_ST_RELOAD_R = period-1;// reload value
  NVIC_ST_CURRENT_R = 0;      // any write to current clears it
  NVIC_SYS_PRI3_R = (NVIC_SYS_PRI3_R&0x00FFFFFF)|0x40000000;           
  NVIC_ST_CTRL_R = 0x05; // Main problem is here, 0x05 means disable interrupt
// 0x07 means enable interrup. but 0x07 doesnt work for me
}

void SysTick_Handler(void){
    GPIO_PORTF_DATA_R ^= 0x04;       // toggle PF2
    Counts = Counts + 1;
    printf("interrupt working\n");
}

//*****************************************************************************
//
// Blink the on-board LED.
//
//*****************************************************************************
int
main(void)
{
    volatile uint32_t ui32Loop;
    unsigned long now;
    //
    // Enable the GPIO port that is used for the on-board LED.
    //
    SYSCTL_RCGC2_R = SYSCTL_RCGC2_GPIOF;

    //
    // Do a dummy read to insert a few cycles after enabling the peripheral.
    //
    ui32Loop = SYSCTL_RCGC2_R;

    //
    // Enable the GPIO pin for the LED (PF2).  Set the direction as output, and
    // enable the GPIO pin for digital function.
    //
    GPIO_PORTF_DIR_R = 0x04;
    GPIO_PORTF_DEN_R = 0x04;

    SysTick_Init(16000);        // initialize SysTick timer, every 1ms

    //
    // Loop forever.
    //
    while(1)
    {     now = NVIC_ST_CURRENT_R;   // get systick current value

          printf("%u\n",now);


          if((NVIC_ST_CTRL_R&0x00010000)!=0){      // check Systick flag
            GPIO_PORTF_DATA_R ^= 0x04;
            printf("timer working\n");
          }
    }
}

---

所有项目文件

可能是上面的SysTick_处理程序没有破坏向量表中的弱绑定。尝试将名称更改为其他名称，并在向量表中进行相同的更改（仅更改DCD xxxxx位），然后查看它是否仍然链接。我按照您的建议执行了操作，现在将转到HardFault\u处理程序。你能下载我的项目并看一下吗。这是我想介绍的应用程序中非常简单的部分，但我仍在尝试运行systick int。提前感谢

// PeriodicSysTickInts.c
// Runs on LM4F120 or TM4C123
// Use the SysTick timer to request interrupts at a particular period.
// Daniel Valvano
// September 14, 2013

/* This example accompanies the book
   "Embedded Systems: Introduction to ARM Cortex M Microcontrollers"
   ISBN: 978-1469998749, Jonathan Valvano, copyright (c) 2013
   Volume 1, Program 9.6

   "Embedded Systems: Real Time Interfacing to ARM Cortex M Microcontrollers",
   ISBN: 978-1463590154, Jonathan Valvano, copyright (c) 2013
   Volume 2, Program 5.12, section 5.7

 Copyright 2013 by Jonathan W. Valvano, valvano@mail.utexas.edu
    You may use, edit, run or distribute this file
    as long as the above copyright notice remains
 THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
 OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
 VALVANO SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL,
 OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
 For more information about my classes, my research, and my books, see
 http://users.ece.utexas.edu/~valvano/
 */

// oscilloscope or LED connected to PF2 for period measurement


#define GPIO_PORTF_DATA_R       (*((volatile unsigned long *)0x400253FC))
#define GPIO_PORTF_DIR_R        (*((volatile unsigned long *)0x40025400))
#define GPIO_PORTF_AFSEL_R      (*((volatile unsigned long *)0x40025420))
#define GPIO_PORTF_DEN_R        (*((volatile unsigned long *)0x4002551C))
#define GPIO_PORTF_AMSEL_R      (*((volatile unsigned long *)0x40025528))
#define GPIO_PORTF_PCTL_R       (*((volatile unsigned long *)0x4002552C))
#define SYSCTL_RCGC2_R          (*((volatile unsigned long *)0x400FE108))
#define NVIC_SYS_PRI3_R         (*((volatile unsigned long *)0xE000ED20))  // Sys. Handlers 12 to 15 Priority
#define NVIC_ST_CTRL_R          (*((volatile unsigned long *)0xE000E010))
#define NVIC_ST_RELOAD_R        (*((volatile unsigned long *)0xE000E014))
#define NVIC_ST_CURRENT_R       (*((volatile unsigned long *)0xE000E018))

void DisableInterrupts(void); // Disable interrupts
void EnableInterrupts(void);  // Enable interrupts
long StartCritical (void);    // previous I bit, disable interrupts
void EndCritical(long sr);    // restore I bit to previous value
void WaitForInterrupt(void);  // low power mode
volatile unsigned long Counts = 0;
// **************SysTick_Init*********************
// Initialize SysTick periodic interrupts
// Input: interrupt period
//        Units of period are 62.5ns (assuming 16 MHz clock)
//        Maximum is 2^24-1
//        Minimum is determined by length of ISR
// Output: none
void SysTick_Init(unsigned long period){
  NVIC_ST_CTRL_R = 0;         // disable SysTick during setup
  NVIC_ST_RELOAD_R = period-1;// reload value
  NVIC_ST_CURRENT_R = 0;      // any write to current clears it
  NVIC_SYS_PRI3_R = (NVIC_SYS_PRI3_R&0x00FFFFFF)|0x40000000; // priority 2
                              // enable SysTick with core clock and interrupts
  NVIC_ST_CTRL_R = 0x07;
  EnableInterrupts();
}
// Interrupt service routine
// Executed every 62.5ns*(period)
void SysTick_Handler(void){
  GPIO_PORTF_DATA_R ^= 0x04;       // toggle PF2
  Counts = Counts + 1;
}
int main(void){
  SYSCTL_RCGC2_R |= 0x00000020; // activate port F
  Counts = 0;
  GPIO_PORTF_DIR_R |= 0x04;   // make PF2 output (PF2 built-in LED)
  GPIO_PORTF_AFSEL_R &= ~0x04;// disable alt funct on PF2
  GPIO_PORTF_DEN_R |= 0x04;   // enable digital I/O on PF2
                              // configure PF2 as GPIO
  GPIO_PORTF_PCTL_R = (GPIO_PORTF_PCTL_R&0xFFFFF0FF)+0x00000000;
  GPIO_PORTF_AMSEL_R = 0;     // disable analog functionality on PF
  SysTick_Init(16000);        // initialize SysTick timer
  EnableInterrupts();

  while(1){                   // interrupts every 1ms, 500 Hz flash
    WaitForInterrupt();
  }
}