Service_USB 4 - Change transfer capacity — Claim/release USB transfer capacity
| R0 | 4 (reason code) | ||||||||
| R1 | &80C00 (USB Service call) | ||||||||
| R2 | Pointer to controller structure | ||||||||
| R3 | device speed | ||||||||
| R4 | transfer type | ||||||||
| R5 | no of bytes to transfer | ||||||||
| R6 | frame repeat (1 at isochronous, 0 at bulk and control,1-255 at interrupt) | ||||||||
| R7 |
|
All registers preserved to pass on, else
| R0 | 0 for success any other value indicates failure. |
| R1 | 0 to claim or preserved to pass on. |
| R2, R3, R4, R5, R6, R7 | preserved |
Must be launched by a configuration application or the USB-Module itself at USB_PipeOpen/USB_PipeClose operation. Every USB host controller driver must support claiming of this Service call. If operation is successful (that means capacity is available, releases are always successful) a 0 must be filled into R0.