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16-BITS OR BUST

by Tom Cantrell

Start ý Unlikely Source ý Under the Hood ý Nihon-no Micon? ý Sources and PDF

I must say, when it comes to dissecting the comings and goings in the MCU market, Iýve always had a bit of trouble figuring out how 16-bit chips fit in. If 8-bit chips are the MCU compact pickup and 32-bit chips are the Corvettes, whatýs that make a 16-bit chip? Is it something that would only appeal to a teenager whose lust for the souped-up is bigger than his budget?

In trying to come up with an answer, part of my problem is simply figuring out what a 16-bit MCU is. Are we talking ALU-width, data bus pins, or programming model? Taking the automotive analogy all the way under the hood, you could think of it as a motor with 16 valves. But, am I talking about a compact pickupýs four-valves-per-cylinder four-cylinder engine or a Corvetteýs two-valves-per-cylinder V8?

The issue has proved a headscratcher for generations of micro marketers and an opportunity for some creative pitching. Even as I peck away, I notice on the wall a late-70s Intel 8088 ad reprint, which crowned that chip the 8-bit Champion over the Zilog Z80 and Motorola 6809. Of course, nowhere does it mention that this particular 8-bit chip, unlike those it planned to vanquish, happened to have a 16-bit ALU.

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