Scott Dattalo <KILLspamPICLISTspamBeGoneMITVMA.MIT.EDU> wrote:

> Has anyone used these [USB PICs]?

   Scott:

   I think Microchip has to actually SHIP one before anyone can use
   it.

> Are they price competive?

   The pricing info that I have (which I received AFTER I resigned
   from the Microchip Consultant Program, so I have no reason to
   believe that it isn't public knowledge) indicates that the USB
   PICs are priced about five times higher than the Cypress M8-based
   USB microcontrollers which currently own over 50% of the
   low-speed USB market.

> I don't need the 480Mb/sec bandwidth in USB 2.0

   Good, because only one semiconductor company has demonstrated
   working USB 2.0 microcontrollers, and USB 2.0 support won't be
   in any Windows operating systems until sometime in 2001, and USB
   2.0 PC motherboards won't be commonly available for a year or
   more.

> in fact the pic devices apparently only support the low speed of
> USB 1.1.

   You have to be careful when discussing USB speeds; "low speed"
   has a very specific meaning.

   There have been three released USB specifications:

       USB 1.0 -- defined a 1.5 Mbit/sec interface ("low speed")
       USB 1.1 -- added a 12 Mbit/sec interface ("full speed")
       USB 2.0 -- added a 480 Mbit/sec interface ("high speed")

   Since each spec is a superset of the earlier ones, it's perfectly
   accurate -- although misleading -- to say that a 1.5-Mbit/sec
   device is "USB 2.0 compliant" or "USB 1.1 compliant".

   Usually, though, "1.0" is verbal shorthand for "1.5 Mbits/sec",
   "1.1" for "12 Mbits/sec", and "2.0" for "480 Mbits/sec".

   If you REALLY want to avoid confusion, it's best to refer to the
   three versions as "low, full, and high speed", or -- even better
   -- as "1.5, 12, and 480 Mbits/second".

   Microchip's USB PICs are limited to the low-speed (1.5 MBit/sec)
   USB rate.

   -Andy


=== Andrew Warren --- spam_OUTaiwspam_OUTcypress.com
=== Cypress Semiconductor Corporation
=== Interface Products Division, S.D.
===
=== The opinions expressed above do
=== not necessarily represent those of
=== Cypress Semiconductor Corporation.

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