Re: Open-collector

Ed Casas (edc@ece.ubc.ca) Sat, 15 Apr 2000 11:59:55 -0700 

Date: Sat, 15 Apr 2000 11:59:55 -0700
From: Ed Casas <edc@ece.ubc.ca>
Subject: Re: Open-collector



On Fri, Apr 14, 2000 at 03:46:01AM -0700, Barry Kwok wrote:

> What determines the data rate for the Universal Serial Bus
> (USB)?

I believe the capabilities of each device are checked by the host
when the device is plugged into the bus.

> How come the data rate is either 1.5 or 12 MB/s?  How come the
> difference is so huge??

The 1.5 Mb/s data rate is meant to be used with very low-rate
devices such as keyboards and mice.  Other things, such as
scanners are expected to use the 12 Mb/s rate.

If you are interested in learning more about USB, the
specification is available on-line at:

	http://www.ti.com/sc/docs/msp/usb/spec/spec1.htm


-- 
Ed Casas   edc@ece.ubc.ca   http://casas.ece.ubc.ca   +1 604 822-2592