On Tue, 6 Feb 2007, Mark Glassberg wrote: > Thanks for the reply, but assuming that I have a usb2 device running on a > usb2 system at less than usb2 speed, how do I correct it?
Your question shows that you don't fully understand the terminology. USB 2.0 is an extension of USB 1.1. It is almost completely compatible, so any USB 1.1 device will work correctly when attached to a USB 2.0 controller and also vice versa: A USB 2.0 device will usually work correctly when attached to a USB 1.1 controller. USB 1.1 defines two bus speeds: 1.5 Mb/s (low) and 12 Mb/s (full). USB 2.0 adds a third bus speed: 480 Mb/s (high). However there is nothing in the standard which says a USB 2.0 device has to run at any particular speed. It is perfectly legal for a USB 2.0 device to support low speed and nothing else. So let's say your device supports high speed. If it is running at less than high speed then something is wrong with the system setup. Maybe the computer's high-speed USB controller isn't working, or maybe the driver for it isn't loaded, or maybe the device is plugged into a port which isn't wired to that controller, etc. To get the device running at high speed, you need to correct whatever problem is present. Alan Stern ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
