Method for realizing robust clock tree comprehensive algorithm for near threshold

Abstract

The invention discloses a method for realizing a robust clock tree comprehensive algorithm for a near threshold. The method comprises the following steps of: 1, generating a symmetric clock tree initial topology by adopting a top-down comprehensive algorithm; and 2, completing buffer insertion on the basis of the generated topological structure, applying the approximate estimation model of the clock skew fluctuation to the buffer insertion process of various buffer sizes, and realizing the optimization process based on a genetic algorithm by taking the optimization of the clock skew fluctuation as a target. According to the implementation method of the robust clock tree comprehensive algorithm for the near threshold, the clock tree comprehensive algorithm takes the symmetrical clock tree as an initial topology to be applied to the near threshold, so that the clock tree is ensured to have very small clock skew. In the buffer insertion stage, a buffer insertion algorithm oriented to a buffer library is realized, and the process realizes selection of an optimal buffer insertion strategy from the buffer library, so that clock deviation fluctuation of a clock tree is as small as possible.

Description

technical field [0001] The invention belongs to the field of electronic design automation in the physical design of integrated circuits, and is a robust optimization method applied to the design of integrated circuit clock trees in low-voltage near-threshold. Background technique [0002] In low-power integrated circuit design, near-threshold design has the highest energy efficiency ratio. The power consumption of the clock tree in the entire circuit design is basically 30%-40%. Therefore, the importance of the clock tree design under the near-threshold for low-power design is self-evident. [0003] Reducing the impact of process fluctuations on design is the most important problem to be solved in near-threshold design, and it is also a point that distinguishes it from constant voltage design. Structurally, the clock tree is mainly composed of clock sources, buffers, interconnect lines and registers. Since the threshold of the transistor at near-threshold is very close to...

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Problems solved by technology

Since the threshold of the transistor is very close to the operating voltage at near-threshold, the fluctuation of the transistor model parameters during the manufacturing process can very significantly affect the timing of the buffer, which in turn affects the skew of the clock tree and the maximum transition time

The timing fluctuation of the clock tree at near-threshold limits the further improvement of circuit performance

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