keypad scanner

That's way too slow a scan rate.

Best regards, Spehro Pefhany

Why the specification for a "Complex programmable logic device"? Is a microcontroller out of the question? That is a programmable logic device, and typically fairly complex, so it _would_ fit your spec, and implementing something like your app in firmware would be a snap - doing it with a big registered gate array would be a freaking nightmare, IM!HO.

Or, just scan it with the contoller itself. What's an "HCS12?"

You can get microcontrollers, like the PIC, that have 16 I/O lines, which would give you 12 for your scanner, and 4 more for data with handshaking. I'm not a PIChead, so have no idea which of the vast family you'd want to choose, but someone here will surely help out in that respect.

Some also recommend AVRs or Basic Stamps - any of these could do the job.

Good Luck! Rich

Probably a homework question from an Indian university.

Successor to the Motorola HC11, from Freescale. They've changed the numbering system a bit... now they have numbers like MC9S12.. Scanning a keyboard would use negligible processing power of any of that series.

Best regards, Spehro Pefhany