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好例２ 1998.9.4
以下の英文は筆者が書きました。特に次の点に注意を払っています。
Computerization of IC Design
Integrated Circuit (IC) design has been dramatically computerized in last twenty years. Twenty years ago, IC design fully depended on manual work on all the steps: logic design, logic verification, circuit design, circuit verification, layout design, and layout verification. Today, logic design and circuit design are partly computerized, layout design is mostly computerized, and all the verifications are fully computerized.
In the early 1970s, IC design fully depended on manual work. Engineers designed logic using their heads and wrote the circuit diagrams on paper with pencils according to the logic. Then, they verified the logic and the circuits with their eyes. After that, engineers designed the circuit layout with pieces of color film according to the circuit diagrams. Then, they verified the layout with their eyes and measures. Finally, they took a photograph of the layout to fabricate the photo-masks.
In the late 1970s, layout design was partly computerized. This computerization was not that computers themselves designed the layout, but that engineers designed the layout with computers instead of the color film. It might be a small step in view of time saving. However, it was a great step in the long view.
In the early 1980s, layout verification was partly computerized. This computerization saved a lot of design time. Engineers did not have to spend a lot of time any more to check all the transistor sizes and all the distances between any two patterns one by one with measures.
In the middle 1980s, circuit design, logic design, circuit verification, and layout design were partly computerized, and layout verification was fully computerized. Engineers registered circuit diagrams with computers, and then verified the circuit logic with computers. Furthermore, Computers themselves designed some of the circuit layout and verified the layout completely. This computerization saved a great deal of design time. Engineers did not have to spend several months any more to verify with their eyes whether the layout plot, sometimes more than 10 m X 10 m, matches the circuits.
In the late 1980s, logic design was partly computerized, and all the verifications were fully computerized. The computerization enabled engineers to design more complicated ICs in shorter periods.
Today, logic design and circuit design are partly computerized, layout design is mostly computerized, and all the verifications are fully computerized. Furthermore, layout design is being computerized more and more. Most of layout engineers may lose their jobs in ten years. Nobody could have forecast the present situation twenty years ago, or can forecast in the coming twenty years. |