我在使用定时器5产生定时中断时发现先设置中断优先级再初始化定时器，定时器不能工作，具体代码如下如果直接在定时器5初始化函数加中断优先级配置则工作正常，请给位大佬帮忙看看。
//中断优先级设置

void NVIC_Configuration(void)
{
        NVIC_InitTypeDef NVIC_InitStructure;
       
        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
       


       

        NVIC_InitStructure.NVIC_IRQChannel = TIM8_UP_IRQn;  //TIM3ÖD¶Ï
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =0;  //ÏèÕ¼óÅÏ輶2¼¶
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  //′óóÅÏ輶0¼¶
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μà±»ê1Äü
        NVIC_Init(&NVIC_InitStructure);  //¸ù¾YNVIC_InitStructÖDÖ¸¶¨μÄ2Îêy3õê¼
       
         NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =0;                //ÏèÕ¼óÅÏ輶        2
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;                                //′óóÅÏ輶                0
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                       
        NVIC_Init(&NVIC_InitStructure);

       
        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
       





       
       
        NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;  //TIM3ÖD¶Ï
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =0;  //ÏèÕ¼óÅÏ輶2¼¶
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  //′óóÅÏ輶0¼¶
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μà±»ê1Äü
        NVIC_Init(&NVIC_InitStructure);

       
               
        NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  //TIM3ÖD¶Ï
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =1;  //ÏèÕ¼óÅÏ輶2¼¶
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  //′óóÅÏ輶0¼¶
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μà±»ê1Äü
        NVIC_Init(&NVIC_InitStructure);
               
        NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;  //TIM3ÖD¶Ï
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =2;  //ÏèÕ¼óÅÏ輶2¼¶
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  //′óóÅÏ輶0¼¶
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μà±»ê1Äü
        NVIC_Init(&NVIC_InitStructure);
               


       

        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
       
        NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn;  //TIM3ÖD¶Ï
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =1;  //ÏèÕ¼óÅÏ輶2¼¶
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  //′óóÅÏ輶0¼¶
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μà±»ê1Äü
        NVIC_Init(&NVIC_InitStructure);
       
       
       
        NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;                                               
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;                //ÏèÕ¼óÅÏ輶        
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;                        //′óóÅÏ輶          0
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       



        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
       
        NVIC_InitStructure.NVIC_IRQChannel = TIM6_IRQn;            
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;                  //ÏèÕ¼óÅÏ輶        1
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;                         //′óóÅÏ輶                0
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                           
        NVIC_Init(&NVIC_InitStructure);   
         

        NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;                //ÏèÕ¼óÅÏ輶        2
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;                                //′óóÅÏ輶                0
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                       
        NVIC_Init(&NVIC_InitStructure);
//        NVIC_SetPriority(SysTick_IRQn,NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0,0));
}


//定时器5初始化
void TIM5_Configuration(void)
{
       
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_SetCounter( TIM5, 0x0000);
  TIM_ClearFlag(TIM5, TIM_FLAG_Update);      
  TIM_ClearITPendingBit(TIM5, TIM_FLAG_Update); //??TIM2???????????
  TIM_ARRPreloadConfig(TIM5, ENABLE);         
  TIM_ITConfig(TIM5, TIM_IT_Update, ENABLE); //??TIM2???   

  TIM_TimeBaseStructure.TIM_Period = 5000;      //????????2000,??????0xffff
  TIM_TimeBaseStructure.TIM_Prescaler =7199;     //??72
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;     // ????
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //????????
  TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure);
  TIM_Cmd(TIM5, ENABLE);       //TIM2 enable counter
       

}