SetFrameLength

This function changes the USB frame length.

Syntax

BOOL SetFrameLength( 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 target value.

uFrameLength

[IN] Specifies the desired frame length.

Return Values

TRUE indicates success. FALSE indicates failure.

Remarks

This function should be used infrequently by client drivers because changing the USB frame length may affect other devices on the bus. The driver must obtain frame-control access by calling the TakeFrameLengthControl function before attempting to change the frame length. To enable devices to adjust to the new frame length, USB requires that frame-length changes be done 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.

This function is defined in the Mousedrv.cpp file.

See Also

ReleaseFrameLengthControl, TakeFrameLengthControl