芯片:STM32F103
想产生1秒的定时,使用TIMER2
void TIM_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
// TIM_OCInitTypeDef TIM_OCInitStructure ;
TIM_DeInit( TIM2);//复位TIM2定时器
/* TIM2 configuration */
TIM_TimeBaseStructure.TIM_Period = 1000 //最大计数值1000
TIM_TimeBaseStructure.TIM_Prescaler = 36000;//分频36000
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; // 时钟分割
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //计数方向向上计数
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
/* Clear TIM2 update pending flag[清除TIM2溢出中断标志] */
TIM_ClearFlag(TIM2, TIM_FLAG_Update);
/* Enable TIM2 Update interrupt [TIM2溢出中断允许]*/
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
/* TIM2 enable counter [允许tim2计数]*/
TIM_Cmd(TIM2, ENABLE);
}
/* PCLK1 = HCLK/2 [低速APB1时钟等于HCLK/2]*/
RCC_PCLK1Config(RCC_HCLK_Div2);
系统时钟是72MHZ,所以APB1时钟为36MHZ
希望能得到1秒的定时,但是实际上有4秒,不知道为什么? |
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