This structure closely matches the structure defined in the USB 2.0 Specification:

typedef struct USB_SetupPacket
{
    USB_BmRequestType_t bmRequestType;    /* (1 byte) Specifies direction of dataflow,
                                             type of rquest and recipient */
    unsigned char bRequest;               /* Specifies the request */
    unsigned short wValue;                /* Host can use this to pass info to the
                                             device in its own way */
    unsigned short wIndex;                /* Typically used to pass index/offset such
                                             as interface or EP no */
    unsigned short wLength;               /* Number of data bytes in the data stage
                                             (for Host -> Device this this is exact
                                             count, for Dev->Host is a max. */
} USB_SetupPacket_t;

• XUD_Result_t USB_GetSetupPacket(XUD_ep ep_out, XUD_ep ep_in, USB_SetupPacket_t &sp)

  Receives a Setup data packet and parses it into the passed USB_SetupPacket_t structure.

  Parameters

  • ep_out

    OUT endpint from XUD

  • ep_in

    IN endpoint to XUD

  • sp

    SetupPacket structure to be filled in (passed by ref)

  Returns

  Returns XUD_RES_OKAY on success, XUD_RES_RST on bus reset

This function takes a populated USB_SetupPacket_t structure as an argument.

• XUD_Result_t USB_StandardRequests(XUD_ep ep_out, XUD_ep ep_in, ?_ARRAY_OF(unsigned char, devDesc_hs), int devDescLength_hs, ?_ARRAY_OF(unsigned char, cfgDesc_hs), int cfgDescLength_hs, ?_ARRAY_OF(unsigned char, devDesc_fs), int devDescLength_fs, ?_ARRAY_OF(unsigned char, cfgDesc_fs), int cfgDescLength_fs, char *unsafe strDescs[], int strDescsLength, USB_SetupPacket_t &sp, XUD_BusSpeed_t usbBusSpeed)

  This function deals with common requests This includes Standard Device Requests listed in table 9-3 of the USB 2.0 Spec all devices must respond to these requests, in some cases a bare minimum implementation is provided and should be extended in the devices EP0 code It handles the following standard requests appropriately using values passed to it:.

  Get Device Descriptor (using devDesc_hs/devDesc_fs arguments)

  Get Configuration Descriptor (using cfgDesc_hs/cfgDesc_fs arguments)

  String requests (using strDesc argument)

  Get Device_Qualifier Descriptor

  Get Other-Speed Configuration Descriptor

  Set/Clear Feature (Endpoint Halt)

  Get/Set Interface

  Set Configuration

  If the request is not recognised the endpoint is marked STALLED

  Parameters

  • ep_out

    Endpoint from XUD (ep 0)

  • ep_in

    Endpoint from XUD (ep 0)

  • devDesc_hs

    The Device descriptor to use, encoded according to the USB standard

  • devDescLength_hs

    Length of device descriptor in bytes

  • cfgDesc_hs

    Configuration descriptor

  • cfgDescLength_hs

    Length of config descriptor in bytes

  • devDesc_fs

    The Device descriptor to use, encoded according to the USB standard

  • devDescLength_fs

    Length of device descriptor in bytes. If 0 the HS device descriptor is used.

  • cfgDesc_fs

    Configuration descriptor

  • cfgDescLength_fs

    Length of config descriptor in bytes. If 0 the HS config descriptor is used.

  • strDescs

  • strDescsLength

  • sp

    USB_SetupPacket_t (passed by ref) in which the setup data is returned

  • usbBusSpeed

    The current bus speed (XUD_SPEED_HS or XUD_SPEED_FS)

  Returns

  Returns XUD_RES_OKAY on success.

USB_StandardRequests() handles the following Standard Device Requests:

• SET_ADDRESS

  • The device address is set in XUD (using XUD_SetDevAddr()).

• SET_CONFIGURATION

  • A global variable is updated with the given configuration value.

• GET_STATUS

  • The status of the device is returned. This uses the device Configuration descriptor to return if the device is bus powered or not.

• SET_CONFIGURATION

  • A global variable is returned with the current configuration last set by SET_CONFIGURATION.

• GET_DESCRIPTOR

  • Returns the relevant descriptors. See Device Descriptors for further details. Note, some changes of returned descriptor will occur based on the current bus speed the device is running.

    • DEVICE
    • CONFIGURATION
    • DEVICE_QUALIFIER
    • OTHER_SPEED_CONFIGURATION
    • STRING

In addition the following test mode requests are dealt with (with the correct test mode set in XUD):

• SET_FEATURE

  • TEST_J
  • TEST_K
  • TEST_SE0_NAK
  • TEST_PACKET
  • FORCE_ENABLE

USB_StandardRequests() handles the following Standard Interface Requests:

• SET_INTERFACE

  • A global variable is maintained for each interface. This is updated by a SET_INTERFACE. Some basic range checking is included using the value numInterfaces from the ConfigurationDescriptor.

• GET_INTERFACE

  • Returns the value written by SET_INTERFACE.

USB_StandardRequests() handles the following Standard Endpoint Requests:

• SET_FEATURE
• CLEAR_FEATURE
• GET_STATUS

If parsing the request does not result in a match, the request is not handled, the Endpoint is marked “Halted” (Using XUD_SetStall_Out() and XUD_SetStall_In()) and the function returns XUD_RES_ERR.

The function returns XUD_RES_OKAY if a request was handled without error (See also Status Reporting).