本帖最后由 aa911 于 2019-6-6 19:41 编辑
由于所用的DEMO版需要，我把第7行改为第8行 ，程序一直在第10行到第14行的地方循环执行，MCU无法正常工作，请问各位问题出在哪？- static void SetSysClock(void)
- {
- __IO uint32_t StartUpCounter = 0, HSEStatus = 0;
-
- /* SYSCLK, HCLK, PCLK configuration ----------------------------------------*/
- /* Enable HSE */
- //RCC->CR |= ((uint32_t)RCC_CR_HSEON);
- RCC->CR &= ~((uint32_t)RCC_CR_HSEON);
- /* Wait till HSE is ready and if Time out is reached exit */
- do
- {
- HSEStatus = RCC->CR & RCC_CR_HSERDY;
- StartUpCounter++;
- } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
- if ((RCC->CR & RCC_CR_HSERDY) != RESET)
- {
- HSEStatus = (uint32_t)0x01;
- }
- else
- {
- HSEStatus = (uint32_t)0x00;
- }
- if (HSEStatus == (uint32_t)0x01)
- {
- /* Enable Prefetch Buffer and set Flash Latency */
- FLASH->ACR = FLASH_ACR_PRFTBE | FLASH_ACR_LATENCY;
-
- /* HCLK = SYSCLK */
- RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
-
- /* PCLK = HCLK */
- RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE_DIV1;
- /* PLL configuration = HSI * 6 = 48 MHz */
- RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
- RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_PREDIV1 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL6);
-
- /* Enable PLL */
- RCC->CR |= RCC_CR_PLLON;
- /* Wait till PLL is ready */
- while((RCC->CR & RCC_CR_PLLRDY) == 0)
- {
- }
- /* Select PLL as system clock source */
- RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
- RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
- /* Wait till PLL is used as system clock source */
- while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)RCC_CFGR_SWS_PLL)
- {
- }
- }
- else
- { /* If HSE fails to start-up, the application will have wrong clock
- configuration. User can add here some code to deal with this error */
- }
- }
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