STM32高级定时器

http://blog.sina.com.cn/s/blog_8240cbef01018dgc.html

2013
/
定时器1的配置 输出两路PWM信号 PA8 PA11
计数时钟为400KHZ 计数溢出大小为40000 /
void Tim1Init(void)
{ 
 GPIO_InitTypeDef GPIO_InitStruct;
 TIM_TimeBaseInitTypeDefTIM_TimeBaseInitStruct;
 TIM_OCInitTypeDef TIM_OCInitStruct;
      
 u16LeftMotor_CCR;  
 u16 RightMotor_CCR;
 
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1
                    | RCC_APB2Periph_GPIOA
                    | RCC_APB2Periph_AFIO, ENABLE);
 
   
 GPIO_InitStruct.GPIO_Pin  = GPIO_Pin_8 | GPIO_Pin_11 ; // 定时器1通道1和4 
 GPIO_InitStruct.GPIO_Mode  =GPIO_Mode_AF_PP;
 GPIO_InitStruct.GPIO_Speed =GPIO_Speed_50MHz;
 GPIO_Init(GPIOA, &GPIO_InitStruct);
 
 
 LeftMotor_CCR = RightMotor_CCR = 2000;
 
  //在APB2设置为72MHZ的基础上，对定时器1进行配置 
 TIM_TimeBaseInitStruct.TIM_RepetitionCounter =0;            //重复计数器无效*/      
 TIM_TimeBaseInitStruct.TIM_CounterMode =TIM_CounterMode_Up; // 向上计数 */
 TIM_TimeBaseInitStruct.TIM_ClockDivision =TIM_CKD_DIV1;     //时钟分频 */
 TIM_TimeBaseInitStruct.TIM_Prescaler =180-1;               // 预分频系数为180-1，计数器时钟为72MHz/180 = 400KHz*/              
 TIM_TimeBaseInitStruct.TIM_Period =40000-1;                 //1)设置计数溢出大小，每计40000个数就产生一个更新事件,
                  2)捕获比较器的值不能大于此值
                  3)计数器时钟400KHZ，每个更新事件为100ms，即脉冲周期为0.1S
                  */ 
 TIM_TimeBaseInit(TIM1,&TIM_TimeBaseInitStruct);
 
 TIM_OCInitStruct.TIM_OutputNState =TIM_OutputNState_Disable;
 
 TIM_OCInitStruct.TIM_OCMode =TIM_OCMode_PWM2;
 TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
 TIM_OCInitStruct.TIM_OCPolarity  = TIM_OCPolarity_Low;

 
 TIM_OCInitStruct.TIM_Pulse =LeftMotor_CCR;  
 TIM_OC1Init(TIM1, &TIM_OCInitStruct);

 
 TIM_OCInitStruct.TIM_Pulse =RightMotor_CCR;
 TIM_OC4Init(TIM1, &TIM_OCInitStruct);

 TIM_Cmd(TIM1, ENABLE);
 TIM_CtrlPWMOutputs(TIM1, ENABLE);
 
}