比如我要输出50Hz的频率,我需要修改例程中哪些参数?
TIM_TimeBaseStructure.TIM_Period = 999; //当定时器从0计数到999,即为1000次,为一个定时周期
TIM_TimeBaseStructure.TIM_Prescaler = 0; //设置预分频:不预分频,即为72MHz
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ; //设置时钟分频系数:不分频
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);//根据TIM_TimeBaseStructure里的值初始化TIM
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //设定TIM的OC模式,配置为PWM模式1
是用72MHz/50Hz=1440000,TIM_Period=1000,TIM_Prescaler=1440000/TIM_Period =1440吗?如果不是该怎么算? |