USB_FrameSyncNumber (SWI&55391) — Tells the USB Module the current USB frame number for a given USB host controller driver.
R0 | Pointer to controller structure. |
R1 | actual USB frame number |
R2 | Reserved. Must be set to zero. |
R3 | Reserved. Must be set to zero. |
R0 | preserved |
R1 | Error code Table A.1 |
R2, R3 | Preserved |
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.
None.