void TIM4_PWM_Init(u16 arr,u16 psc)

{  

GPIO_InitTypeDef GPIO_InitStructure;

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);// 

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB , ENABLE);  //

   //

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; //TIM4_CH1

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;  //

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; //

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

TIM_TimeBaseStructure.TIM_Period = arr; //

TIM_TimeBaseStructure.TIM_Prescaler =psc; //

TIM_TimeBaseStructure.TIM_ClockDivision = 0; //

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //

TIM_OCInitStructure.TIM_Pulse = 0; //

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //

TIM_OC1Init(TIM4, &TIM_OCInitStructure);  //

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //

TIM_OCInitStructure.TIM_Pulse = 0; //

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //

TIM_OC2Init(TIM4, &TIM_OCInitStructure);  //

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //

TIM_OCInitStructure.TIM_Pulse = 0; //

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //

TIM_OC3Init(TIM4, &TIM_OCInitStructure);  //

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //

TIM_OCInitStructure.TIM_Pulse = 0; //

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //

TIM_OC4Init(TIM4, &TIM_OCInitStructure);  //

  TIM_CtrlPWMOutputs(TIM4,ENABLE); //

TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);  //

TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);  //

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);  //

TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);  //

TIM_ARRPreloadConfig(TIM4, ENABLE); //

TIM_Cmd(TIM4, ENABLE);  //

}