stm32f469 PWN not output NState ？

[ac.2]

My project needs to output PWM NState， My code is as follows, but no PWM signal output has been detected by the oscilloscope measurement. How can I solve this problem?

#define MOTOR_DE_RCC_PERIPH RCC_AHB1Periph_GPIOC
#define MOTOR_DE_PORT GPIOC
#define MOTOR_DE_PIN GPIO_Pin_6
 
#define MOTOR_PWM_RCC_PERIPH RCC_AHB1Periph_GPIOC
#define MOTOR_PWM_TIMER_PERIPH RCC_APB2Periph_TIM8 
#define MOTOR_PWM_PORT GPIOC
#define MOTOR_PWM_PIN GPIO_Pin_7
 
#define MOTOR_PWM_AF GPIO_AF_TIM8
#define MOTOR_PWM_TIM TIM8
#define MOTOR_PWM_PIN_SOURCE GPIO_PinSource7
 
#define PWM_FREQ 100 // 100 Hz
#define PWM_INITIAL_PULSE 1000 
 
void bsp_motor_output_nstate (void)
{
 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
 TIM_OCInitTypeDef TIM_OCInitStructure;
 GPIO_InitTypeDef GPIO_InitStructure;
 uint16_t usPeriod;
 uint16_t usPrescaler;
 uint32_t uiTIMxCLK;
 
 // enable GPIO clock
 if(MOTOR_PWM_RCC_PERIPH == MOTOR_DE_RCC_PERIPH)
 {
 RCC_AHB1PeriphClockCmd(MOTOR_DE_RCC_PERIPH, ENABLE);
 }
 else
 {
 RCC_AHB1PeriphClockCmd(MOTOR_DE_RCC_PERIPH, ENABLE);
 RCC_AHB1PeriphClockCmd(MOTOR_PWM_RCC_PERIPH, ENABLE);
 }
 
 //configure GPIO 
 GPIO_InitStructure.GPIO_Pin = MOTOR_DE_PIN;		
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;	
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;	
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;	
 GPIO_Init(MOTOR_DE_PORT, &GPIO_InitStructure);
 
 GPIO_WriteBit(MOTOR_DE_PORT, MOTOR_DE_PIN, Bit_RESET); 
 
 /* confiure motor PWM timer */
 // enable tiemr clk
 RCC_APB2PeriphClockCmd(MOTOR_PWM_TIMER_PERIPH, ENABLE);
 
 //configure GPIO
 GPIO_InitStructure.GPIO_Pin = MOTOR_PWM_PIN;	
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
 GPIO_Init(MOTOR_PWM_PORT, &GPIO_InitStructure);
 
 // link to AF function 
 GPIO_PinAFConfig(MOTOR_PWM_PORT, MOTOR_PWM_PIN_SOURCE, MOTOR_PWM_AF);
 
 // configure PWM Freq
 uiTIMxCLK = SystemCoreClock;
 
 if(PWM_FREQ < 100)
 {
 usPrescaler = 10000 - 1;
 usPeriod = (uiTIMxCLK / 10000) / PWM_FREQ - 1;	
 }
 else if(PWM_FREQ < 3000)
 {
 usPrescaler = 100 - 1;					
 usPeriod = (uiTIMxCLK / 100) / PWM_FREQ - 1;	
 }
 else
 {
 usPrescaler = 0;					
 usPeriod = uiTIMxCLK / PWM_FREQ - 1;	
 }
 
 // Time base configuration 
 TIM_TimeBaseStructure.TIM_Period = usPeriod;
 TIM_TimeBaseStructure.TIM_Prescaler = usPrescaler;
 TIM_TimeBaseStructure.TIM_ClockDivision = 0;
 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
 TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0000;		// TIM1 and TIM8 must setting	
 
 TIM_TimeBaseInit(MOTOR_PWM_TIM, &TIM_TimeBaseStructure);
 
 // PWM1 Mode configuration: Channel2 
 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
 TIM_OCInitStructure.TIM_Pulse = (PWM_INITIAL_PULSE * usPeriod) / 10000;
 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
	
 TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;	// only for TIM1 and TIM8. 	
 TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;	// only for TIM1 and TIM8. 		
 TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;	// only for TIM1 and TIM8. 
 TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;	// only for TIM1 and TIM8. 
 
 TIM_OC2Init (MOTOR_PWM_TIM, &TIM_OCInitStructure);
 TIM_OC2PreloadConfig(MOTOR_PWM_TIM, TIM_OCPreload_Enable);
 
 TIM_ARRPreloadConfig(MOTOR_PWM_TIM, ENABLE);
 
 // TIMx enable counter 
 TIM_Cmd (MOTOR_PWM_TIM, ENABLE);
 TIM_CtrlPWMOutputs (MOTOR_PWM_TIM, ENABLE);
}