STM32F746G-DISCOVERY PWM输出问题

需要在ARD D10（PI0，TIM5-CH4）输出PWM方波，好像没有输出，查了两天，没有查出问题，请大侠帮忙看看，程序如下：
1）GPIO-CONFIG
GPIO_InitTypeDef  gpio_init_structure;
__HAL_RCC_GPIOI_CLK_ENABLE();
gpio_init_structure.Pin = GPIO_PIN_0;
gpio_init_structure.Mode = GPIO_MODE_AF_PP;
gpio_init_structure.Speed = GPIO_SPEED_HIGH;
gpio_init_structure.Alternate = GPIO_AF2_TIM5;;
HAL_GPIO_Init(GPIOI, &gpio_init_structure);
/* Set TIMx instance */
TimHandle.Instance = TIM5;
PWM_Width = (uint32_t) ((SystemCoreClock /2) / Ferequency_SetValue) - 1;       
TimHandle.Init.Period = PWM_Width;
TimHandle.Init.Prescaler = 1;
TimHandle.Init.ClockDivision = 0;
TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;               
if(HAL_TIM_Base_Init(&TimHandle) != HAL_OK)
{
        while(1){        }
}
TIMOC_Config.OCMode = TIM_OCMODE_PWM1;
TIMOC_Config.Pulse = PWM_Width>>1;
TIMOC_Config.OCIdleState = TIM_OCIDLESTATE_SET;
TIMOC_Config.OCPolarity = TIM_OCPOLARITY_HIGH ;
HAL_TIM_PWM_ConfigChannel(&TimHandle,&TIMOC_Config,TIM_CHANNEL_4)；               
HAL_TIMEx_PWMN_Start(&TimHandle, TIM_CHANNEL_4);
if(HAL_TIM_Base_Start(&TimHandle) != HAL_OK)
{
        while(1) {}
}
//在void HAL_TIM_Base_MspInit(TIM_HandleTypeDef *htim)里
__HAL_RCC_TIM5_CLK_ENABLE();

F7还没有用到过，不是很清楚，有波形吗？？

直接用cube配置，然后就hal库函数，就可以输出pwm。。

PWM_Width = (uint32_t) ((SystemCoreClock /2) / Ferequency_SetValue) - 1;
这个是什么作用啊？？？

只是根据PWM值计算ARR值

还没用过这个呢

使用CUBE的TIM5程序
/* TIM5 init function */
void MX_TIM5_Init(void)
{

  TIM_ClockConfigTypeDef sClockSourceConfig;
  TIM_MasterConfigTypeDef sMasterConfig;
  TIM_OC_InitTypeDef sConfigOC;

  htim5.Instance = TIM5;
  htim5.Init.Prescaler = 2;
  htim5.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim5.Init.Period = 49999;
  htim5.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  HAL_TIM_Base_Init(&htim5);

  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  HAL_TIM_ConfigClockSource(&htim5, &sClockSourceConfig);

  HAL_TIM_PWM_Init(&htim5);

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  HAL_TIMEx_MasterConfigSynchronization(&htim5, &sMasterConfig);

  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 24999;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  HAL_TIM_PWM_ConfigChannel(&htim5, &sConfigOC, TIM_CHANNEL_4);

}
结果也一样：没有输出，哪位大侠看看撒