Concepts
The General USB Process
The Enumeration Process:What happens when a device is connected?
Software – General
Interrupt transfer mode
isochronous transfer mode
bulk transfer mode
3.As the host enumerates each device it sets aside bandwidth for the devices that use the interrupt and isochronous transfer modes and keeps track of the total bandwidth used.
These two transfer modes can use up to 90%
of the total bandwidth. | TM |
|
4.Once 90% of
the available bandwidth is used up, the host does not allow any other interrupt or isochronous devices to be enumerated and the host uses the remaining bandwidth of at least 10% for control transfer packets and bulk transfer packets.
