Editorial: March 14, 1996

Processor vendors were the first to cave in to the demands of the power equation. When you're slinging 10 million transistors onto a silicon slab, your choice is to drop the operating voltage or close your IC fab. Building processors that tolerate 5V interface levels is a stopgap measure. All system-logic voltage supplies are headed down, as are interface levels.

I realize that it's still not easy to design 3V-only systems or systems that run exclusively on even lower voltages. A lot of the silicon that goes into such systems must necessarily be custom. But, now is the time to seriously consider such custom designs because parts are scarce anyway. Custom silicon may be a way of ensuring some parts from the IC vendor.

However, ensuring part availability isn't the most important reason for dropping your designs' supply voltages. Viability is. We no longer design with tens, hundreds, or even thousands of transistors. We use millions and think little of the number. One lowly 1-Mbit DRAM, now considered an aging jellybean part, has more than 1 million transistors on it. RISC µPs, those kings of "low-transistor-count" processor design, now sport millions of transistors. Although the RISC processor cores need "only" a few tens of thousands of transistors, on-chip RAM caches that feed the little processor's ravenous maw consume hundreds of thousands, or millions, of transistors.

The best way to beat the heat in modern systems is not to generate it in the first place. So, just what is your plan for migrating to low-voltage design?

Steven H. Leibson
Editor In Chief