进不了PWM的中断，请大佬请教是我配置错了嘛？

void PWM_init(uint32_t period ){

////设置系统时钟为16MHZ//定时都要初始化始终；
////SysCtlClockSet(SYSCTL_SYSDIV_1 |SYSCTL_USE_OSC | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);
//设置系统时钟为80MHZ//定时都要初始化始终；
SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_MAIN_OSC_DIS | SYSCTL_OSC_INT |SYSCTL_USE_PLL);
//一分频
SysCtlPWMClockSet(SYSCTL_PWMDIV_1);
//使能//使能函数都是同一个 
SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM0);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);

//配置相应的管脚 
GPIOPinConfigure(GPIO_PB6_M0PWM0);
GPIOPinConfigure(GPIO_PB7_M0PWM1);
GPIOPinTypePWM(GPIO_PORTB_BASE,GPIO_PIN_6|GPIO_PIN_6|GPIO_PIN_7) ; 
//配置PWM发生器
PWMGenConfigure(PWM0_BASE, PWM_GEN_0,PWM_GEN_MODE_DOWN | PWM_GEN_MODE_NO_SYNC);//设置周期PWMGenPeriodSet(PWM0_BASE, PWM_GEN_0, period);//设置输出高电平时间
//PWMPulseWidthSet(PWM0_BASE, PWM_OUT_0, 100);//PWMPulseWidthSet(PWM0_BASE, PWM_OUT_1, 300);//使能PWM的发生器
PWMGenEnable(PWM0_BASE, PWM_GEN_0);PWMGenEnable(PWM0_BASE, PWM_GEN_1);

PWMGenIntTrigEnable(PWM0_BASE, PWM_GEN_0,PWM_TR_CNT_ZERO );
PWMGenIntRegister(PWM0_BASE, PWM_GEN_0,count_step);
IntMasterEnable();
//使能输出PWMOutputState(PWM0_BASE, (PWM_OUT_0_BIT | PWM_OUT_1_BIT), true);
//PWMOutputState(PWM0_BASE, (PWM_OUT_0_BIT | PWM_OUT_1_BIT),false);禁止

}