US Patent 7797474 Method and apparatus for enhancing universal serial bus applications

A system for enhancing universal serial bus (USB) applications comprises an upstream processor, a downstream processor and a main controller. The upstream processor accepts standard USB signals from a USB host and independently provides responses required by USB specification within the required time frame. The downstream processor connectable to USB-compliant devices accepts the USB signals from the USB-compliant devices and provides responses required by USB specification within the required time frame. The main controller interconnects the upstream and downstream processors, and provides timing independence between upstream and downstream timing.