Designer Reference Manual
USB08 Evaluation Board
168
Universal USB Device Driver (USBIO)
MOTOROLA
Universal USB Device Driver (USBIO)
IOCTL_USBIO_GET_CURRENT_FRAME_NUMBER
The IOCTL_USBIO_GET_CURRENT_FRAME_NUMBER operation
returns the current value of the frame number counter that is maintained
by the USBD.
lpInBuffer
Not used with this operation. Set to Null.
nInBufferSize
Not used with this operation. Set to zero.
lpOutBuffer
Pointer to a buffer that will receive an USBIO_FRAME_NUMBER
(
) data structure.
nOutBufferSize
Specifies the size, in bytes, of the buffer pointed to by
lpOutBuffer
,
which has to be at least sizeof(USBIO_FRAME_NUMBER) for this
operation.
Comments
The returned frame number is a 32 bit value. The lower 11 bits of this
value correspond to the frame number value in the Start Of Frame token
on the bus.