CPU design at the gate level

From: Richard Erlacher <edick_at_idcomm.com>
Date: Fri Nov 2 16:33:22 2001

While it's true that TTL and work-alike CMOS is found everywhere, if you go with
a parts list, you'll find you're unable to get a substantial range of parts
these days. You may be able to find the parts eventually, but the investment in
shipping is prohibitive.

Unfortunately for the builders of "one-of's," like me (spelled one-off's in some
places, for reasons I don't understand), the programmable logic comes in
packages that are really inconvenient for that purpose. Nowadays, you're
required to use a 1000+ pin BGA package to get the quantity of logic that you'd
like in a 44-pin PLCC. If you're really lucky with the fit, the device will
allow you to use 10% of the gate count the marketing guys said you're paying
for. The result is that you have to use a PGA package that lists for over $1k
per part, or build an adapter board for the cheaper TQFP part, with a total
cost, when you're done, of over $1k per each anyway, and then, to make matters
worse, only one in 7 of these adapter boards will turn out to be properly
soldered, so you waste 6 FPGA's costing $300 each. That's why product
development that once required a cash outlay of $500 now costs $500 million.

Dick

----- Original Message -----
From: "Iggy Drougge" <optimus_at_canit.se>
To: "Ben Franchuk" <classiccmp_at_classiccmp.org>
Sent: Friday, November 02, 2001 1:37 PM
Subject: Re: CPU design at the gate level


> Ben Franchuk skrev:
>
> >Never used the stuff. Since they don't make TTL any more I kind was
> >forced into using FPGA's. :).
>
> What? My local electronics shop owner tells me that it isn't as high-profile
> nowadays, but it's quite possible to buy 74 series circuits in any good
> electronics shop, right?
>
> --
> En ligne avec Thor 2.6a.
>
> Anv?nd g?rna mitt staket, fast du beh?ver nog fr?scha upp det lite.
> Lupin III, Lupin den otrolige (Lupin III vs. fukusei ningen), TMS 1978
>
>
>
Received on Fri Nov 02 2001 - 16:33:22 GMT