USB_FrameSyncNumber (SWI&55391)
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## Name

USB_FrameSyncNumber (SWI&55391) — Tells the USB Module the current USB frame number for a given USB host controller driver.

## On Entry

R0 | Pointer to controller structure.
R1 | actual USB frame number
R2 | Reserved. Must be set to zero.
R3 | Reserved. Must be set to zero.

## On Exit

R0 | preserved
R1 | Error code Table A.1
R2, R3 | Preserved

## Use

An USB host controller driver must tell the actual USB frame number every time if a new frame is starting at its USB. This causes a lot of action internal in the USB module. Note that the number given must not exceed the limit given by the frame number mask of the USB host controller properties.

## Related SWI's

None.

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