/// <summary>
        /// Builds a configuration-selection request.
        /// </summary>
        /// <param name="interfaces">The interface information field.</param>
        /// <param name="configDescriptor">The configuration descriptor.</param>
        /// <returns>The configuration-selection request.</returns>
        public TS_URB_SELECT_CONFIGURATION BuildSelectConfigRequest(
            TS_USBD_INTERFACE_INFORMATION[] interfaces,
            byte[] configDescriptor
            )
        {
            TS_URB_SELECT_CONFIGURATION req = new TS_URB_SELECT_CONFIGURATION(
                this.requestId,
                this.noAck
                );
            // TS_URB_HEADER (8 bytes) + ConfigurationDescriptorIsValid (1 byte) + Padding (3 bytes)
            // NumInterfaces (4 bytes) + TS_USBD_INTERFACE_INFORMATION + USB_CONFIGURATION_DESCRIPTOR
            int interfaceLength = 0;

            foreach (TS_USBD_INTERFACE_INFORMATION i in interfaces)
            {
                interfaceLength += i.Length;
            }
            req.Header.Size                    = (ushort)(8 + 1 + 3 + 4 + interfaceLength + configDescriptor.Length);
            req.Header.URB_Function            = URB_FUNCTIONID.URB_FUNCTION_SELECT_CONFIGURATION;
            req.Interfaces                     = interfaces;
            req.NumInterfaces                  = (uint)interfaces.Length;
            req.UsbConfDesc                    = configDescriptor;
            req.ConfigurationDescriptorIsValid = (configDescriptor != null ? (byte)1 : (byte)0);
            return(req);
        }
        public TS_URB ParsePdu(byte[] data)
        {
            TS_URB urb;

            switch (GetTsUrbType(data))
            {
            // Indicates to the host controller driver that a configuration is to be selected
            case URB_FUNCTIONID.URB_FUNCTION_SELECT_CONFIGURATION:
                urb = new TS_URB_SELECT_CONFIGURATION();
                break;

            // Indicates to the host controller driver that an alternate interface setting is being selected for an interface.
            // If set, the URB is used with _URB_SELECT_INTERFACE as the data structure.
            case URB_FUNCTIONID.URB_FUNCTION_SELECT_INTERFACE:
                urb = new TS_URB_SELECT_INTERFACE();
                break;

            // Indicates that all outstanding requests for a pipe should be canceled.
            case URB_FUNCTIONID.URB_FUNCTION_ABORT_PIPE:

            // Resets the indicated pipe.
            case URB_FUNCTIONID.URB_FUNCTION_SYNC_RESET_PIPE_AND_CLEAR_STALL:

            // Clears the halt condition on the host side of a pipe.
            // If set, this URB is used with _URB_PIPE_REQUEST as the data structure.
            case URB_FUNCTIONID.URB_FUNCTION_SYNC_RESET_PIPE:

            // Clears the stall condition on the endpoint. For all pipes except isochronous pipes.
            case URB_FUNCTIONID.URB_FUNCTION_SYNC_CLEAR_STALL:
                urb = new TS_URB_PIPE_REQUEST();
                break;

            // Requests the current frame number from the host controller driver.
            case URB_FUNCTIONID.URB_FUNCTION_GET_CURRENT_FRAME_NUMBER:
                urb = new TS_URB_GET_CURRENT_FRAME_NUMBER();
                break;

            // Transfers data to or from a control pipe.
            case URB_FUNCTIONID.URB_FUNCTION_CONTROL_TRANSFER:
                urb = new TS_URB_CONTROL_TRANSFER();
                break;

            // Transfers data from a bulk pipe or interrupt pipe or to an bulk pipe.
            case URB_FUNCTIONID.URB_FUNCTION_BULK_OR_INTERRUPT_TRANSFER:
                urb = new TS_URB_BULK_OR_INTERRUPT_TRANSFER();
                break;

            // Transfers data to or from an isochronous pipe.
            case URB_FUNCTIONID.URB_FUNCTION_ISOCH_TRANSFER:
                urb = new TS_URB_ISOCH_TRANSFER();
                break;

            // Retrieves the device descriptor from a specific USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_DESCRIPTOR_FROM_DEVICE:

            // Retrieves the descriptor from an endpoint on an interface for a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_DESCRIPTOR_FROM_ENDPOINT:

            // Sets a device descriptor on a device.
            case URB_FUNCTIONID.URB_FUNCTION_SET_DESCRIPTOR_TO_DEVICE:

            // Sets an endpoint descriptor on an endpoint for an interface.
            case URB_FUNCTIONID.URB_FUNCTION_SET_DESCRIPTOR_TO_ENDPOINT:

            // Retrieves the descriptor from an interface for a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_DESCRIPTOR_FROM_INTERFACE:

            // Sets a descriptor for an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_SET_DESCRIPTOR_TO_INTERFACE:
                urb = new TS_URB_CONTROL_DESCRIPTOR_REQUEST();
                break;

            // Sets a USB-defined feature on a device.
            case URB_FUNCTIONID.URB_FUNCTION_SET_FEATURE_TO_DEVICE:

            // Sets a USB-defined feature on an endpoint for an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_SET_FEATURE_TO_ENDPOINT:

            // Sets a USB-defined feature on an interface for a device.
            case URB_FUNCTIONID.URB_FUNCTION_SET_FEATURE_TO_INTERFACE:

            // Sets a USB-defined feature on a device-defined target on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_SET_FEATURE_TO_OTHER:

            // Clears a USB-defined feature on a device.
            case URB_FUNCTIONID.URB_FUNCTION_CLEAR_FEATURE_TO_DEVICE:

            // Clears a USB-defined feature on an endpoint, for an interface, on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_CLEAR_FEATURE_TO_ENDPOINT:

            // Clears a USB-defined feature on an interface for a device.
            case URB_FUNCTIONID.URB_FUNCTION_CLEAR_FEATURE_TO_INTERFACE:

            // Clears a USB-defined feature on a device defined target on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_CLEAR_FEATURE_TO_OTHER:
                urb = new TS_URB_CONTROL_FEATURE_REQUEST();
                break;

            // Retrieves status from a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_STATUS_FROM_DEVICE:

            // Retrieves status from an endpoint for an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_STATUS_FROM_ENDPOINT:

            // Retrieves status from an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_STATUS_FROM_INTERFACE:

            // Retrieves status from a device-defined target on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_STATUS_FROM_OTHER:
                urb = new TS_URB_CONTROL_GET_STATUS_REQUEST();
                break;

            // Sends a vendor-specific command to a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_VENDOR_DEVICE:

            // Sends a vendor-specific command for an endpoint on an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_VENDOR_ENDPOINT:

            // Sends a vendor-specific command for an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_VENDOR_INTERFACE:

            // Sends a vendor-specific command to a device-defined target on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_VENDOR_OTHER:

            // Sends a USB-defined class-specific command to a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_CLASS_DEVICE:

            // Sends a USB-defined class-specific command to an endpoint, on an interface, on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_CLASS_ENDPOINT:

            // Sends a USB-defined class-specific command to an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_CLASS_INTERFACE:

            // Sends a USB-defined class-specific command to a device defined target on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_CLASS_OTHER:
                urb = new TS_URB_CONTROL_VENDOR_OR_CLASS_REQUEST();
                break;

            // Retrieves the current configuration on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_CONFIGURATION:
                urb = new TS_URB_CONTROL_GET_CONFIGURATION_REQUEST();
                break;

            // Retrieves the current settings for an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_INTERFACE:
                urb = new TS_URB_CONTROL_GET_INTERFACE_REQUEST();
                break;

            // Retrieves a Microsoft OS feature descriptor from a USB device or an interface on a USB device.
            case URB_FUNCTIONID.URB_FUNCTION_GET_MS_FEATURE_DESCRIPTOR:
                urb = new TS_URB_OS_FEATURE_DESCRIPTOR_REQUEST();
                break;

            // Transfers data to or from a control pipe without a time limit specified by a timeout value.
            case URB_FUNCTIONID.URB_FUNCTION_CONTROL_TRANSFER_EX:
                urb = new TS_URB_CONTROL_TRANSFER_EX();
                break;

            default:
                urb = new TS_URB_UNKNOWN();
                break;
            }

            if (!PduMarshaler.Unmarshal(data, urb))
            {
                urb = new TS_URB_UNKNOWN();
                PduMarshaler.Unmarshal(data, urb);
            }
            return(urb);
        }