后来去看了，ST官方的资料，其实那本参考手册上有两个例的，现在放在这里，大家一起学习


/** 00574   * @brief  Sets System clock frequency to 72MHz and configure HCLK, PCLK2  00575   *         and PCLK1 prescalers.  00576   * @param  None 00577   * @retval None 00578   */ 00579 void SetSysClockTo72(void) 00580 { 00581   /* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/    00582   /* RCC system reset(for debug purpose) */ 00583   RCC_DeInit(); 00584  00585   /* Enable HSE */ 00586   RCC_HSEConfig(RCC_HSE_ON); 00587  00588   /* Wait till HSE is ready */ 00589   HSEStartUpStatus = RCC_WaitForHSEStartUp(); 00590  00591   if (HSEStartUpStatus == SUCCESS) 00592   { 00593     /* Enable Prefetch Buffer */ 00594     FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable); 00595  00596     /* Flash 2 wait state */ 00597     FLASH_SetLatency(FLASH_Latency_2); 00598   00599     /* HCLK = SYSCLK */ 00600     RCC_HCLKConfig(RCC_SYSCLK_Div1);  00601    00602     /* PCLK2 = HCLK */ 00603     RCC_PCLK2Config(RCC_HCLK_Div1);  00604  00605     /* PCLK1 = HCLK/2 */ 00606     RCC_PCLK1Config(RCC_HCLK_Div2); 00607  00608 #ifdef STM32F10X_CL 00609     /* Configure PLLs *********************************************************/ 00610     /* PLL2 configuration: PLL2CLK = (HSE / 5) * 8 = 40 MHz */ 00611     RCC_PREDIV2Config(RCC_PREDIV2_Div5); 00612     RCC_PLL2Config(RCC_PLL2Mul_8); 00613  00614     /* Enable PLL2 */ 00615     RCC_PLL2Cmd(ENABLE); 00616  00617     /* Wait till PLL2 is ready */ 00618     while (RCC_GetFlagStatus(RCC_FLAG_PLL2RDY) == RESET) 00619     {} 00620  00621     /* PLL configuration: PLLCLK = (PLL2 / 5) * 9 = 72 MHz */  00622     RCC_PREDIV1Config(RCC_PREDIV1_Source_PLL2, RCC_PREDIV1_Div5); 00623     RCC_PLLConfig(RCC_PLLSource_PREDIV1, RCC_PLLMul_9); 00624 #else 00625     /* PLLCLK = 8MHz * 9 = 72 MHz */ 00626     RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9); 00627 #endif 00628  00629     /* Enable PLL */  00630     RCC_PLLCmd(ENABLE); 00631  00632     /* Wait till PLL is ready */ 00633     while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET) 00634     { 00635     } 00636  00637     /* Select PLL as system clock source */ 00638     RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); 00639  00640     /* Wait till PLL is used as system clock source */ 00641     while(RCC_GetSYSCLKSource() != 0x08) 00642     { 00643     } 00644   } 00645   else 00646   { /* If HSE fails to start-up, the application will have wrong clock configuration. 00647        User can add here some code to deal with this error */     00648  00649     /* Go to infinite loop */ 00650     while (1) 00651     { 00652     } 00653   } 00654 }



这个是设置到72M的例子

设置107系统时钟到56M.txt 下载积分: 积分 -1 分

2.61 KB, 下载次数: 42, 下载积分: 积分 -1 分

这个是官方的资料

设置107的系统时钟到72M.txt 下载积分: 积分 -1 分

2.61 KB, 下载次数: 153, 下载积分: 积分 -1 分

这个是官方的资料