break;
      case USB_ENDPOINT_DESCRIPTOR_TYPE:
        if (ifn == SetupPacket.wIndex.WB.L) {
          n = ((USB_ENDPOINT_DESCRIPTOR *)pD)->bEndpointAddress & 0x8F;
          m = (n & 0x80) ? ((1 << 16) << (n & 0x0F)) : (1 << n);
          if (alt == SetupPacket.wValue.WB.L) {
            USB_EndPointMask |=  m;
            USB_EndPointHalt &= ~m;
            USB_ConfigEP((USB_ENDPOINT_DESCRIPTOR *)pD);
            USB_EnableEP(n);
            USB_ResetEP(n);
            msk |= m;
          }
          else if ((alt == old) && ((msk & m) == 0)) {
            USB_EndPointMask &= ~m;
            USB_EndPointHalt &= ~m;
            USB_DisableEP(n);
          }
        }
        break;
    }
    (BYTE *)pD += pD->bLength;
  }
  return (set);
}


/*
 *  USB Endpoint 0 Event Callback
 *    Parameter:       event
 */

void USB_EndPoint0 (DWORD event) {

  switch (event) {

    case USB_EVT_SETUP:
      USB_SetupStage();
      USB_DirCtrlEP(SetupPacket.bmRequestType.BM.Dir);
      EP0Data.Count = SetupPacket.wLength;
      switch (SetupPacket.bmRequestType.BM.Type) {

        case REQUEST_STANDARD:
          switch (SetupPacket.bRequest) {

            case USB_REQUEST_GET_STATUS:
              if (!USB_GetStatus()) {
                goto stall_i;
              }
              break;

            case USB_REQUEST_CLEAR_FEATURE:
              if (!USB_SetClrFeature(0)) {
                goto stall_i;
              }
              USB_StatusInStage();
#if USB_FEATURE_EVENT
              USB_Feature_Event();
#endif
              break;

            case USB_REQUEST_SET_FEATURE:
              if (!USB_SetClrFeature(1)) {
                goto stall_i;
              }
              USB_StatusInStage();
#if USB_FEATURE_EVENT
              USB_Feature_Event();
#endif
              break;

            case USB_REQUEST_SET_ADDRESS:
              switch (SetupPacket.bmRequestType.BM.Recipient) {
                case REQUEST_TO_DEVICE:
                  USB_DeviceAddress = 0x80 | SetupPacket.wValue.WB.L;
                  USB_StatusInStage();
                  break;
                default:
                  goto stall_i;
              }
              break;

            case USB_REQUEST_GET_DESCRIPTOR:
              if (!USB_GetDescriptor()) {
                goto stall_i;
              }
              break;

            case USB_REQUEST_SET_DESCRIPTOR:
/*stall_o:*/  USB_SetStallEP(0x00);
              EP0Data.Count = 0;
              break;

            case USB_REQUEST_GET_CONFIGURATION:
              switch (SetupPacket.bmRequestType.BM.Recipient) {
                case REQUEST_TO_DEVICE:
                  EP0Data.pData = &USB_Configuration;
                  USB_DataInStage();
                  break;
                default:
                  goto stall_i;
              }
              break;

            case USB_REQUEST_SET_CONFIGURATION:
              switch (SetupPacket.bmRequestType.BM.Recipient) {
                case REQUEST_TO_DEVICE:
                  if (!USB_SetConfiguration()) {
                    goto stall_i;
                  }
                  USB_StatusInStage();
#if USB_CONFIGURE_EVENT
                  USB_Configure_Event();
#endif
                  break;
                default:
                  goto stall_i;
              }
              break;

            case USB_REQUEST_GET_INTERFACE:
              switch (SetupPacket.bmRequestType.BM.Recipient) {
                case REQUEST_TO_INTERFACE:
                  if ((USB_Configuration != 0) &&
                      (SetupPacket.wIndex.WB.L < USB_NumInterfaces)) {
                    EP0Data.pData = USB_AltSetting + SetupPacket.wIndex.WB.L;
                    USB_DataInStage();
                  } else {
                    goto stall_i;
                  }
                  break;
                default:
                  goto stall_i;
              }
              break;

            case USB_REQUEST_SET_INTERFACE:
              switch (SetupPacket.bmRequestType.BM.Recipient) {
                case REQUEST_TO_INTERFACE:
                  if (!USB_SetInterface()) {
                    goto stall_i;
                  }
                  USB_StatusInStage();
#if USB_INTERFACE_EVENT
                  USB_Interface_Event();
#endif
                  break;
                default:
                  goto stall_i;
              }
              break;

            default:
              goto stall_i;

          }
          break;

        case REQUEST_CLASS:
#if USB_CLASS
          switch (SetupPacket.bmRequestType.BM.Recipient) {
            case REQUEST_TO_INTERFACE:
#if USB_HID
              if (SetupPacket.wIndex.WB.L == USB_HID_IF_NUM) {
                switch (SetupPacket.bRequest) {
                  case HID_REQUEST_GET_REPORT:
                    if (HID_GetReport()) {
                      EP0Data.pData = EP0Buf;
                      USB_DataInStage();
                      goto class_ok;
                    }
                    break;
                  case HID_REQUEST_SET_REPORT:
                    EP0Data.pData = EP0Buf;
                    goto class_ok;
                  case HID_REQUEST_GET_IDLE:
                    if (HID_GetIdle()) {
                      EP0Data.pData = EP0Buf;
                      USB_DataInStage();
                      goto class_ok;
                    }
                    break;
                  case HID_REQUEST_SET_IDLE:
                    if (HID_SetIdle()) {
                      USB_StatusInStage();
                      goto class_ok;
                    }
                    break;
                  case HID_REQUEST_GET_PROTOCOL:
                    if (HID_GetProtocol()) {
                      EP0Data.pData = EP0Buf;
                      USB_DataInStage();
                      goto class_ok;
                    }
                    break;
                  case HID_REQUEST_SET_PROTOCOL:
                    if (HID_SetProtocol()) {
                      USB_StatusInStage();
                      goto class_ok;
                    }
                    break;
                }
              }
#endif  /* USB_HID */
#if USB_MSC
              if (SetupPacket.wIndex.WB.L == USB_MSC_IF_NUM) {
                switch (SetupPacket.bRequest) {
                  case MSC_REQUEST_RESET:
                    if (MSC_Reset()) {
                      USB_StatusInStage();
                      goto class_ok;
                    }
                    break;
                  case MSC_REQUEST_GET_MAX_LUN:
                    if (MSC_GetMaxLUN()) {
                      EP0Data.pData = EP0Buf;
                      USB_DataInStage();
                      goto class_ok;
                    }
                    break;
                }
              }
#endif  /* USB_MSC */
#if USB_AUDIO
              if ((SetupPacket.wIndex.WB.L == USB_ADC_CIF_NUM)  ||
                  (SetupPacket.wIndex.WB.L == USB_ADC_SIF1_NUM) ||
                  (SetupPacket.wIndex.WB.L == USB_ADC_SIF2_NUM)) {
                if (SetupPacket.bmRequestType.BM.Dir) {
                  if (ADC_IF_GetRequest()) {
                    EP0Data.pData = EP0Buf;
                    USB_DataInStage();
                    goto class_ok;
                  }
                } else {
                  EP0Data.pData = EP0Buf;
                  goto class_ok;
                }
              }
#endif  /* USB_AUDIO */
#if USB_CDC
              if ((SetupPacket.wIndex.WB.L == USB_CDC_CIF_NUM)  ||
                  (SetupPacket.wIndex.WB.L == USB_CDC_DIF_NUM)) {
                switch (SetupPacket.bRequest) {
                  case CDC_SEND_ENCAPSULATED_COMMAND:
                    EP0Data.pData = EP0Buf;      /* data to be stored, see USB_EVT_OUT */
                    goto class_ok;
                    break;
                  case CDC_GET_ENCAPSULATED_RESPONSE:
                    if (CDC_GetEncapsulatedResponse()) {
                      EP0Data.pData = EP0Buf;    /* data to be sent */
                      USB_DataInStage();         /* send data */
                      goto class_ok;
                    }
                    break;
                  case CDC_SET_COMM_FEATURE:
                    EP0Data.pData = EP0Buf;      /* data to be stored, see USB_EVT_OUT */
                    goto class_ok;
                    break;
                  case CDC_GET_COMM_FEATURE:
                    if (CDC_GetCommFeature(SetupPacket.wValue.W)) {
                      EP0Data.pData = EP0Buf;    /* data to be sent */
                      USB_DataInStage();         /* send data */
                      goto class_ok;
                    }
                    break;
                  case CDC_CLEAR_COMM_FEATURE:
                    if (CDC_ClearCommFeature(SetupPacket.wValue.W)) {
                      USB_StatusInStage();       /* send Acknowledge */
                      goto class_ok;
                    }
                    break;
                  case CDC_SET_LINE_CODING:
                    EP0Data.pData = EP0Buf;      /* data to be stored, see USB_EVT_OUT */
                    goto class_ok;
                    break;
                  case CDC_GET_LINE_CODING:
                    if (CDC_GetLineCoding()) {
                      EP0Data.pData = EP0Buf;    /* data to be sent */
                      USB_DataInStage();         /* send data */
                      goto class_ok;
                    }
                    break;
                  case CDC_SET_CONTROL_LINE_STATE:
                    if (CDC_SetControlLineState(SetupPacket.wValue.W)) {
                      USB_StatusInStage();       /* send Acknowledge */
                      goto class_ok;
                    }
                    break;
                  case CDC_SEND_BREAK:
                    if (CDC_SendBreak(SetupPacket.wValue.W)) {
                      USB_StatusInStage();       /* send Acknowledge */
                      goto class_ok;
                    }
                    break;
                }
              }
#endif  /* USB_CDC */
              goto stall_i;
#if USB_AUDIO
            case REQUEST_TO_ENDPOINT:
              if (SetupPacket.bmRequestType.BM.Dir) {
                if (ADC_EP_GetRequest()) {
                  EP0Data.pData = EP0Buf;
                  USB_DataInStage();
                  goto class_ok;
                }
              } else {
                EP0Data.pData = EP0Buf;
                goto class_ok;
              }
              goto stall_i;
#endif  /* USB_AUDIO */
            default:
              goto stall_i;
          }
class_ok: break;
#else
          goto stall_i;
#endif  /* USB_CLASS */

        case REQUEST_VENDOR:
          goto stall_i;

        default:
stall_i:  USB_SetStallEP(0x80);
          EP0Data.Count = 0;
          break;

      }
      break;

    case USB_EVT_OUT:
      if (SetupPacket.bmRequestType.BM.Dir == 0) {
        if (EP0Data.Count) {
          USB_DataOutStage();                    /* receive data */
          if (EP0Data.Count == 0) {
            switch (SetupPacket.bmRequestType.BM.Type) {
              case REQUEST_STANDARD:
                goto stall_i;
#if (USB_CLASS)
              case REQUEST_CLASS:
                switch (SetupPacket.bmRequestType.BM.Recipient) {
                  case REQUEST_TO_INTERFACE:
#if USB_HID
                    if (SetupPacket.wIndex.WB.L == USB_HID_IF_NUM) {
                      if (!HID_SetReport()) {
                        goto stall_i;
                      }
                      break;
                    }
#endif /* USB_HID */  
#if USB_AUDIO
                    if ((SetupPacket.wIndex.WB.L == USB_ADC_CIF_NUM)  ||
                        (SetupPacket.wIndex.WB.L == USB_ADC_SIF1_NUM) ||
                        (SetupPacket.wIndex.WB.L == USB_ADC_SIF2_NUM)) {
                      if (!ADC_IF_SetRequest()) {
                        goto stall_i;
                      }
                      break;
                    }
#endif /* USB_AUDIO */
#if USB_CDC
                    if ((SetupPacket.wIndex.WB.L == USB_CDC_CIF_NUM)  ||
                        (SetupPacket.wIndex.WB.L == USB_CDC_DIF_NUM)) {
                      switch (SetupPacket.bRequest) {
                        case CDC_SEND_ENCAPSULATED_COMMAND:
                          if (!CDC_SendEncapsulatedCommand()) {
                            goto stall_i;
                          }
                          break;
                        case CDC_SET_COMM_FEATURE:
                          if (!CDC_SetCommFeature(SetupPacket.wValue.W)) {
                            goto stall_i;
                          }
                          break;
                        case CDC_SET_LINE_CODING:
                          if (!CDC_SetLineCoding()) {
                            goto stall_i;
                          }
                          break;
                      } /* end switch (SetupPacket.bRequest) */ 
                      break;
                    }
#endif /* USB_CDC */
                    goto stall_i;
                  case REQUEST_TO_ENDPOINT:
#if USB_AUDIO
                    if (ADC_EP_SetRequest()) break;
#endif /* USB_AUDIO */
                    goto stall_i;
                  default:
                    goto stall_i;
                }
                break;
#endif /* USB_CLASS */
              default:
                goto stall_i;
            }
            USB_StatusInStage();                 /* send Acknowledge */
          }
        }
      } else {
        USB_StatusOutStage();                    /* receive data */
      }
      break;

    case USB_EVT_IN:
      if (SetupPacket.bmRequestType.BM.Dir == 1) {
        USB_DataInStage();                       /* send data */
      } else {
        if (USB_DeviceAddress & 0x80) {
          USB_DeviceAddress &= 0x7F;
          USB_SetAddress(USB_DeviceAddress);
        }
      }
      break;

    case USB_EVT_IN_STALL:
      USB_ClrStallEP(0x80);
      break;

    case USB_EVT_OUT_STALL:
      USB_ClrStallEP(0x00);
      break;

  }
}