CPU design at the gate level

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(a)canit.se> To: "Ben Franchuk" <classiccmp(a)classiccmp.org> Sent: Friday, November 02, 2001 1:37 PM Subject: Re: CPU design at the gate level