mcpwm_intr_status值一直为零，没有产生tez或tep中断，为什么？

ESP32-WROOM-32UE
comit: af8bc4c

/**
* @brief this is ISR handler function
*/
static void IRAM_ATTR isr_handler()
{
    uint32_t mcpwm_intr_status;
    mcpwm_intr_status = MCPWM[MCPWM_UNIT_0]->int_st.val; //Read interrupt status
    tmp = mcpwm_intr_status;
    MCPWM[MCPWM_UNIT_0]->int_clr.val = mcpwm_intr_status;
}

   mcpwm_config_t pwm_config;
    pwm_config.frequency = 5000; //frequency = 1000Hz, i.e. for every servo motor time period should be 1ms
    pwm_config.cmpr_a = 50;      //duty cycle of PWMxA = 0
    pwm_config.cmpr_b = 50;      //duty cycle of PWMxb = 0
    pwm_config.counter_mode = MCPWM_UP_COUNTER;
    pwm_config.duty_mode = MCPWM_DUTY_MODE_0;
    mcpwm_init(MCPWM_UNIT_0, MCPWM_TIMER_0, &pwm_config);                          //Configure PWM0A & PWM0B with above settings
    MCPWM[MCPWM_UNIT_0]->int_ena.timer0_tez_int_ena = 1;
    MCPWM[MCPWM_UNIT_0]->int_ena.timer0_tep_int_ena = 1;
    mcpwm_isr_register(MCPWM_UNIT_0, isr_handler, NULL, ESP_INTR_FLAG_IRAM, NULL); //Set ISR Handler
   printf("TMR0TEZ intr status %d n", tmp);

mcpwm_intr_status值一直为零，没有产生tez或tep中断。