stm32中断优先级

求助各位   STM32程序中有CAN中断和TIM4中断 想让CAN中断优先级大于TIM4   TIM4是用来发PWM波的   进入TIM4中断发现CAN通信不正常了
void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;
  /* Enable the TIM3 gloabal Interrupt*/
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
  NVIC_InitStructure.NVIC_IRQChannel =  USB_LP_CAN1_RX0_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =1 ;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority =0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  
  NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority =2;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure); ｝
麻烦各位

是不是要改  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =1 ;对应1,2,3，试试。