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在调试STM32F103V8时,碰到一个问题。 外部输入时钟8M晶体,内部设置倍频参数为16,这个时候依然可以工作,且速度确实比倍频参数为8时快一倍。不知道为什,请大家帮帮忙。
程序如下: #define portd_4r (*(vu8 *)0x42220208) #define portd_4s (*(vu8 *)0x42220288)
RCC_DeInit();
RCC_HSEConfig(RCC_HSE_ON);
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if(HSEStartUpStatus == SUCCESS) { FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
FLASH_SetLatency(FLASH_Latency_2); RCC_HCLKConfig(RCC_SYSCLK_Div1); RCC_PCLK2Config(RCC_HCLK_Div1);
RCC_PCLK1Config(RCC_HCLK_Div2);
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_16);
RCC_PLLCmd(ENABLE);
while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET) { }
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE); /* Configure PC.06, PC.07, PC.08 and PC.09 as Output push-pull */ // For STM3210B-LK1, configure PC.04-PC.07 instead GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_2; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_Init(GPIOC, &GPIO_InitStructure);
while (1) { portd_4r = 1; portd_4s = 1; } |
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