时钟设置

2万 · 2020-12-14 23:56

同样的定时器程序NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);/
      delay_init(168);  //
      LED_Init();                               //

      TIM3_Int_Init(5000-1,8400-1);
      while(1)
      {
            LED0=!LED0;//DS0·-×a
            delay_ms(200);//
      };
我用例子里面的代码，定时500ms，刷写到原子的板子是500ms,刷写到我的板子变2s,隔了4倍。。晶振都是一样的。。这是为什么？

2万 · 2020-12-15 18:53

把系统时钟读出来，测试下，现在的时钟倍频到多少

2万 · 2020-12-15 18:57

一样的程序一样的设置，时钟也都是8M的。。。

2万 · 2020-12-15 19:01

只是两块PCB不同。。。

2万 · 2020-12-15 19:05

void delay_init(u8 SYSCLK)
{
#if SYSTEM_SUPPORT_OS                                              //Èç¹ûÐèÒªÖ§³ÖOS.
      u32 reload;
#endif
      SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8);
      fac_us=SYSCLK/8;                                              //²»ÂÛÊÇ·ñÊ¹ÓÃOS,fac_us¶¼ÐèÒªÊ¹ÓÃ
#if SYSTEM_SUPPORT_OS                                              //Èç¹ûÐèÒªÖ§³ÖOS.
      reload=SYSCLK/8;                                              //Ã¿ÃëÖÓµÄ¼ÆÊý´ÎÊý µ¥Î»ÎªM
      reload*=1000000/delay_ostickspersec;       //¸ù¾Ýdelay_ostickspersecÉè¶¨Òç³öÊ±¼ä
                                                                                    //reloadÎª24Î»¼Ä´æÆ÷,×î´óÖµ:16777216,ÔÚ168MÏÂ,Ô¼ºÏ0.7989s×óÓÒ
      fac_ms=1000/delay_ostickspersec;             //´ú±íOS¿ÉÒÔÑÓÊ±µÄ×îÉÙµ¥Î»
      SysTick->CTRL|=SysTick_CTRL_TICKINT_Msk;          //¿ªÆôSYSTICKÖÐ¶Ï
      SysTick->LOAD=reload;                                        //Ã¿1/delay_ostickspersecÃëÖÐ¶ÏÒ»´Î
      SysTick->CTRL|=SysTick_CTRL_ENABLE_Msk;       //¿ªÆôSYSTICK
#else
      fac_ms=(u16)fac_us*1000;                               //·ÇOSÏÂ,´ú±íÃ¿¸ömsÐèÒªµÄsystickÊ±ÖÓÊý
#endif
}

2万 · 2020-12-15 19:08

void SystemInit(void)
{
  /* FPU settings ------------------------------------------------------------*/
  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  /* set CP10 and CP11 Full Access */
  #endif
  /* Reset the RCC clock configuration to the default reset state ------------*/
  /* Set HSION bit */
  RCC->CR |= (uint32_t)0x00000001;

  /* Reset CFGR register */
  RCC->CFGR = 0x00000000;

  /* Reset HSEON, CSSON and PLLON bits */
  RCC->CR &= (uint32_t)0xFEF6FFFF;

  /* Reset PLLCFGR register */
  RCC->PLLCFGR = 0x24003010;

  /* Reset HSEBYP bit */
  RCC->CR &= (uint32_t)0xFFFBFFFF;

  /* Disable all interrupts */
  RCC->CIR = 0x00000000;

#if defined (DATA_IN_ExtSRAM) || defined (DATA_IN_ExtSDRAM)
  SystemInit_ExtMemCtl();
#endif /* DATA_IN_ExtSRAM || DATA_IN_ExtSDRAM */

  /* Configure the System clock source, PLL Multiplier and Divider factors,
   AHB/APBx prescalers and Flash settings ----------------------------------*/
  SetSysClock();

  /* Configure the Vector Table location add offset address ------------------*/
#ifdef VECT_TAB_SRAM
  SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
#else
  SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
#endif
}