USB Data Structures

These are the data structures defined by the USL for USB device descriptors. The current definitions can also be found in the USB.h file.

Driver Plug-in Dispatch Table Structure

The driver dispatch table used to match and initialize the appropriate driver with a device is of the form shown here. This structure is filled in by the class driver.



 
struct USBClassDriverPluginDispatchTable {

    UInt32                          pluginVersion; 

                                   /* Version number of this */

                                   /* plugin for the dispatch table */

    USBDValidateHWProcPtr             validateHWProc; 


                                   /* Pointer to */


                                   /* the procedure the driver */ 


                                   /* uses to verify that device is */


                                   /* the proper hardware */

    USBDInitializeDeviceProcPtr       initializeDeviceProc; 


                                   /* Pointer to */


                                   /* the procedure that initializes */


                                   /* the class driver */

    USBDInitializeInterfaceProcPtr    initializeInterfaceProc; 


                                   /* Pointer to procedure that */


                                   /* initializes a particular */


                                   /* interface in the class driver.*/

     USBDFinalizeProcPtr            finalizeProc; 


                                   * Pointer to the procedure that */


                                   /* finalizes the class driver */

    USBDDriverNotifyProcPtr         notificationProc; 


                                   /* Pointer to the procedure that */


                                   /* passes notifications to */


                                   /* the driver */

Device Descriptor Structure

The USB device descriptor is of this form:



 
struct USBDeviceDescriptor {

    UInt8   length;

    UInt8   descType;

    UInt16  usbRel;

    UInt8   deviceClass;

    UInt8   deviceSubClass;

    UInt8   protocol;

    UInt8   maxPacketSize;

    UInt16  vendor;

    UInt16  product;

    UInt16  devRel;

    UInt8   manuIdx;

    UInt8   prodIdx;

    UInt8   serialIdx;

    UInt8   numConf;

    UInt16  descEnd;

};

Configuration Descriptor Structure

The USB device configuration descriptor is of this form:



 
struct USBConfigurationDescriptor {

    UInt8   length;

    UInt8   descriptorType;

    UInt16  totalLength;

    UInt8   numInterfaces;

    UInt8   configValue;

    UInt8   configStrIndex;

    UInt8   attributes;

    UInt8   maxPower;

};

Interface Descriptor Structure

The USB device interface descriptor is of this form:



 
struct USBInterfaceDescriptor {

    UInt8   length;

    UInt8   descriptorType;

    UInt8   interfaceNumber;

    UInt8   alternateSetting;

    UInt8   numEndpoints;

    UInt8   interfaceClass;

    UInt8   interfaceSubClass;

    UInt8   interfaceProtocol;

    UInt8   interfaceStrIndex;

};

Endpoint Descriptor Structure

The USB device endpoint descriptor is of this form:



 
struct USBEndPointDescriptor {

    UInt8   length;

    UInt8   descriptorType;

    UInt8   endpointAddress;

    UInt8   attributes;

    UInt16  maxPacketSize;

    UInt8   interval;

};

HID Descriptor Structure

The USB HID descriptor is of this form:



 
struct USBHIDDescriptor {

    UInt8   descLen;

    UInt8   descType;

    UInt16  descVersNum;

    UInt8   hidCountryCode;

    UInt8   hidNumDescriptors;

    UInt8   hidDescriptorType;

    UInt8   hidDescriptorLengthLo;

    UInt8   hidDescriptorLengthHi;

};

HID Report Descriptor Structure

The USB HID report descriptor is of this form:



 
struct USBHIDReportDesc {

    UInt8   hidDescriptorType;

    UInt8   hidDescriptorLengthLo;

    UInt8   hidDescriptorLengthHi;

};

Hub Port Status Structure

The hub port status structure is of this form:



 
struct USBHubPortStatus {

    UInt16   portFlags;
        /* Port status flags */

    UInt16   portChangeFlags;   /* Port changed flags */

};