Friday, January 21, 2005
Chapter 4- Endpoint Types
The Universal Serial Bus specification defines four transfer/endpoint types,
Click the respective transfers for detail information ....
1.Control Transfers
2.Interrupt Transfers
3.Isochronous Transfers
4.Bulk Transfers
Bandwidth Management
The host is responsible in managing the bandwidth of the bus. This is done at enumeration when configuring Isochronous and Interrupt Endpoints and throughout the operation of the bus. The specification places limits on the bus, allowing no more than 90% of any frame to be allocated for periodic transfers (Interrupt and Isochronous) on a full speed bus. On high speed buses this limitation gets reduced to no more than 80% of a microframe can be allocated for periodic transfers.
So you can quite quickly see that if you have a highly saturated bus with periodic transfers, the remaining 10% is left for control transfers and once those have been allocated, bulk transfers will get its slice of what is left.
Chapter 5 <<>> Chapter3
Click the respective transfers for detail information ....
1.Control Transfers
2.Interrupt Transfers
3.Isochronous Transfers
4.Bulk Transfers
Bandwidth Management
The host is responsible in managing the bandwidth of the bus. This is done at enumeration when configuring Isochronous and Interrupt Endpoints and throughout the operation of the bus. The specification places limits on the bus, allowing no more than 90% of any frame to be allocated for periodic transfers (Interrupt and Isochronous) on a full speed bus. On high speed buses this limitation gets reduced to no more than 80% of a microframe can be allocated for periodic transfers.
So you can quite quickly see that if you have a highly saturated bus with periodic transfers, the remaining 10% is left for control transfers and once those have been allocated, bulk transfers will get its slice of what is left.
Chapter 5 <<>> Chapter3
