Lpc2000

Rick,

You are probably correct.  I was simply pointing out that, while meeting the
USB 2.0 spec, the chips do not support high-speed transfers (to a lot of
people USB 2.0 and high-speed are synonymous when in fact high-speed
transfers are simply an option under 2.0).  

FWIW, we tried interfacing a Cypress EZ-USB SX2 chip to a '2106.  The GPIO
on the '2106 simply was not fast enough to keep up with the configuration
timing requirements of the SX2 so we abandoned the attempt.  Fortunately,
for our purposes, full-speed (12Mbps) is fast enough and there are lots of
options in that arena.

Curt

-----Original Message-----
From: Rick Collins [mailto:gnuarm@...] 
Sent: Saturday, January 08, 2005 12:26 AM
To: lpc2000@yahoogroups.com
Subject: [lpc2000] Re: New file uploaded to lpc2000



--- In lpc2000@yahoogroups.com, "Curt Powell" <curt.powell@s...> wrote:
> Charles,
> 
> These appear to be USB 2.0 full speed (12 Mbps) devices, not high
speed (480
> Mbps) devices, correct?   If so then they don't differ much from
other USB
> interface chips such as those from ftdi, except possibly lower 
> component counts.

I'm pretty sure you won't find any high speed USB chips with an integrated
physical interface (PHY).  I seem to recall that the high speed interface
requires something fundamentally different in the chip design that would
require additional mask layers, so it makes the chip less cost effective.
Is you need high speed, you can count on using a separate PHY chip for now.


I just did a search and found a number of articles about IP vendors adding
USB PHY cores to their product line.  So it may not be too much longer
before we see interface chips for high speed with the integrated PHY.  





 
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