28027采用PWM触发ADC采样没有成功触发

PWM_setCounterMode(pwmHandle, PWM_CounterMode_Up);         // Count up        PWM_setPeriod(pwmHandle, EPWM4_tiMER_TBPRD);               // Set timer period        PWM_disableCounterLoad(pwmHandle);                         // Disable phase loading        PWM_setPhase(pwmHandle, 0x0000);                           // Phase is 0        PWM_setCount(pwmHandle, 0x0000);                           // Clear counter        PWM_setHighSpeedClkDiv(pwmHandle, PWM_HspClkDiv_by_1);     // Clock ratio to SYSCLKOUT        PWM_setClkDiv(pwmHandle, PWM_ClkDiv_by_1);        // Setup shadow register load on ZERO                PWM_setShadowMode_CmpB(pwmHandle, PWM_ShadowMode_Shadow);                PWM_setLoadMode_CmpB(pwmHandle, PWM_LoadMode_Zero);        // Set Compare values        PWM_setCmpB(pwmHandle, EPWM4_CMPB);    // Set Compare B value        // Set actions        PWM_setActionQual_Zero_PwmB(pwmHandle, PWM_ActionQual_Set);            // Set PWM4B on Zero        PWM_setActionQual_CntUp_CmpB_PwmB(pwmHandle, PWM_ActionQual_Clear);    // Clear PWM4B on event B, up count        PWM_enableSocAPulse(pwmHandle);   // Enable SOC on A group        PWM_setSocAPulseSrc(pwmHandle, PWM_SocPulseSrc_CounterEqualCmpBIncr);   // Select SOC from from CPMB on upcount        PWM_setSocAPeriod(pwmHandle,PWM_SocPeriod_FirstEvent);  // Generate pulse on 1st eventADC_setSocTrigSrc(adcHandle,ADC_SocNumber_0,ADC_SocTrigSrc_EPWM4_ADCSOCB);
1、采用PWM触发ADC 采样，但是并没有成功触发，配置如上代码，哪里出了问题？
2、28027手册中并没有高速时钟的设置介绍，是否28027不使用外部高速时钟？而库里面配置PWM时基时钟时却用到了高速时钟？