On the relationship among accuracy, tolerance and compensation in the deep sub-micron era

Historically, ASIC solutions tended to be effective because the physics and scale of most production technologies allowed circuit designers (and circuit design tools) to safely abstract physical properties: the size and performance of chips could largely be predicted based on logical structure alone. But those days are going fast, and with the advent of 500 K+ gate chips in deep sub-micron (DSM) technologies, new approaches must be found, This paper starts with some background in technology trends, and then reviews the traditional "over the wall" methodology. Section 3 then proposes a "limited loops" design flow based on estimation, floorplanning, and the effective cooperation of synthesis and gate-level placement technologies. This flow is discussed from the perspective of error in the estimation processes and the ability of subsequent steps to tolerate and compensate for the error.