Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!udel!rochester!pt.cs.cmu.edu!gandalf.cs.cmu.edu!lindsay
From: lindsay@gandalf.cs.cmu.edu (Donald Lindsay)
Newsgroups: comp.arch
Subject: Re: Mass produced custom chips
Message-ID: <12742@pt.cs.cmu.edu>
Date: 21 Apr 91 22:11:59 GMT
References: <3329@crdos1.crd.ge.COM>
Organization: Carnegie Mellon
Lines: 44

In article <3329@crdos1.crd.ge.COM> davidsen@crdos1.crd.ge.com 
	(bill davidsen) writes:
>Will the day ever come when we can fast build custom CPUs?
>  - fully automated chip layout.
>  - A program the customer could run on a PC or workstation to select
>    the options, and then send then in by email, floppy, or whatever.
>  - direct computer controlled chip generation without a mask.

There was a project a few years ago (U Arizona??) with the motto "Ada
to Silicon". I believe they claimed some success. So, the idea of
highly automated chip layout has been around a few times.

On another tack, see "Building and Using a Highly Parallel
Programmable Logic Array", IEEE Computer, Jan 1991 p.81. This is the
Splash system: software, plus a VME board containing 32 Xilinx FPGAs,
each with RAM. The software isn't as high level as you wish, but
there is a class of problems where they routinely run an order of
magnitude faster than a Cray-2 or a CM-2.

On the fabrication side, the trend has been to what you might call
megafabs, with long construction times and nine digit price tags. I
have been listening for years for hints that a minifab or microfab
could be built, and things are looking up. The military tends to need
very small production runs, so they have pushed for flexible
multipurpose equipment - for instance, machines that can do several
steps to a set of wafers before being reloaded. Add in ideas like
"clean boxes", the rise of fab-equipment interface standards, FIBs
(Focussed Ion Beams), laser and E-beam direct-write technologies,
solid-state laser/plasma x-ray sources, x-ray mirrors, etc and it
seems guaranteed that fab technology will evolve. Will the evolution
allow microfabs? Gee, I don't know. I have this dream of a truck
pulling up to the EE department's loading dock and leaving a
0.1-micron facility .. but just because an x-ray source will be small
(take that, IBM!) does not imply that the whole fab will be a small
enough number of units, and state-of-the-art, too.

To end on an enthusiastic note: I just saw a wonderful photo.  It
showed a corner of a 68040, before-and-after they used FIB to cut two
traces (!!) and run a patch wire (!!!!!!). The claim was that they
had designed unconnected bits of logic into odd places around the
chip, so that they could, say, cut out an inverter, and patch in a
nand in its place. Wow. In fact, gosh golly wow.
-- 
Don		D.C.Lindsay 	Carnegie Mellon Robotics Institute