Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!ogccse!blake!caesar!icsu6000
From: icsu6000@caesar.cs.montana.edu (Jaye Mathisen)
Newsgroups: comp.lang.forth
Subject: Re: Cost of Forth Chips
Keywords: forth
Message-ID: <2429@caesar.cs.montana.edu>
Date: 27 Aug 89 06:39:42 GMT
Organization: Montana State University, Dept. of Computer Science, Bozeman
Lines: 46

I'm posting this for a friend, please direct comments, flames, remarks
to him.  His email address is given in his article.

 >From ieekw Mon Aug 21 12:55:59 1989
 >Date: Mon, 21 Aug 89 12:55:51 mdt
 >From: ieekw (Winters)
 >To: dali!caesar!indri!aplcen!mef
 >Subject: Re: Cost of Forth Chips
 >Newsgroups: comp.lang.forth
 >In-Reply-To: <2709@aplcen.apl.jhu.edu>
 >References: <893@mtk.UUCP>
 >Organization: Montana State University 
 >Cc: ieekw
 >Status: R
 >
 >From an architectural standpoint, I do not see a great cost difference
 >between Forth and RISC processors.  Both have controllers of 
 >tightly constrained complexity, and fairly generic datapaths.  Beyond
 >this, die area depends on the amount of on-die memory desired: cache
 >memory for RISCs, register space for Berkeley-style RISCs, or stack memory
 >for Forth processors.  It has been pointed out that the greatest difference 
 >in current processors is implementation: most RISCS are full custom
 >designs while the RTX and SC32 processors are semi-custom.  While
 >Marty Fraeman is correct in emphasizing the importance of die size
 >(Eldredge's Law: die cost varies with the cube of die area--from the
 >old Hewlett-Packard school of IC design) while citing potential area
 >gains from migrating the SC32 to a full custom realization, it should
 >be pointed out that such gains would likely apply only to the datapath
 >and controller portions of the processor.  The memory modules are
 >typically assembled from similar compiler tools in either methodology.
 >I suspect that performance gains would outweigh cost gains in moving
 >to full custom Forth processors.  (Not to discourage anyone, I think
 >it's still a good idea).
 >
 >On the other hand, die costs appear to be much less significant than
 >marketing considerations in processor pricing.  The real question is when
 >the market for Forth processors will support the low-margin pricing
 >that RISC producers think about and CISC producers enjoy.
 >
 >Kel Winters
 >Montana State University 
 >ieekw@caesar.cs.montana.edu
 >
 >"How do we do it? Volume, Volume, Volume."   - David Letterman 
 >
 >