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LPSET_FRAME_LENGTH (Compact 2013)

  • Article

3/26/2014

This function changes the universal serial bus (USB) frame length.

Syntax

typedef BOOL (* LPSET_FRAME_LENGTH)(
  USB_HANDLE hDevice, 
  HANDLE hEvent, 
  USHORT uFrameLength
);

Parameters

  • hDevice
    [in] Handle to a USB device.
  • hEvent
    [in] Handle to an event to signal when the frame length reaches the target value.
  • uFrameLength
    [in] Desired frame length.

Return Value

TRUE indicates success. FALSE indicates failure.

Remarks

Client drivers should sparingly use this function because changing the USB frame length can affect other devices on the bus. The driver must obtain frame-control access by calling the LPTAKE_FRAME_LENGTH_CONTROL function before attempting to change the frame length. To enable devices to adjust to the new frame length, USB requires that frame-length changes occur gradually, over a period of frames, instead of abruptly jumping to the target frame length. The client driver passes in an event handle, which is signaled once the frame length has reached the target.

This function does not always set exactly the requested length.

Requirements

Header

usbdi.h

See Also

Reference

USB Driver Functions
LPRELEASE_FRAME_LENGTH_CONTROL
LPTAKE_FRAME_LENGTH_CONTROL