riscy
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IDT 3730 peripheral interface chip

To: riscy@pyramid.com
Subject: IDT 3730 peripheral interface chip
From: caret@pyramid.com (Neil Russell)
Date: Thu, 1 Jul 93 14:43:15 PDT
This is the wonder chip that makes a lot of this design easy.  It
handles the DRAM/VRAM interface in such a way to take full
advantage of the short-cuts offered by DRAM (interleaving,
page-mode access, early-write mode, etc).  Also, it has
some 11 DMA channels and logic to interface to slower and thinner
busses.

The existance of this chip means that Steven Liggett (sp?) will
conceed to not using the 3041, as he intended in his design (the
3041 is a cheap, stripped r3k that Steve planned to use to
fill the void created by not having things like the 3730).

Now, the problem.  In the spec's that I have, this chip is
preliminary.  I have spoken to IDT and they expect to release the
chip some time around September.  After the release, their distributors
still have to stock up before we can get them.  I have been trying
to get IDT to give me advance information and some samples, but
they are trying to ignore me (it seems), probably because we are
small time.

Right now, there is no reasonable alternative to this device, other
than designing the equivalent ourselves.  Steve has suggested using
an FPGA or some other similar large Gate Array.  I'm not too pleased
with this idea because it means that we have to depend on expensive
hardware and software to program them.  The only alternative is to
use regular PALs, but this will use a fair amount of real-estate.

The decision now is whether we go for it now, using PALs, or wait
6 months and use what's available then.  If we wait, there could be
a real possibility of using the R4200 and getting some real
performance.  Given the speed that this project is going, it could
well be 6 months before we are ready anyhow, in which case we
should design now with the release date set some time around X-mas.


Comments?

-- 
Neil Russell            (The wizard from OZ)
Pyramid Technology                      Email:  caret@pyramid.com
3860 N. First Street                    Voice:  (408) 428-7302
San Jose, CA 95134-1702                   FAX:  (408) 428-8845

 

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