Eecient Retiming of Large Circuits
نویسندگان
چکیده
| Retiming, introduced by Leiserson and Saxe, is a powerful transformation of circuits that preserves functionality and improves performance. The ASTRA algorithm proposed an alternative view of retiming using the equivalence between retiming and clock skew optimization, and also presented a fast algorithm for minimum period (minperiod) retiming. Since minperiod retiming may signi cantly increase the number of ipops in the circuit, minimum area (minarea) retiming is an important problem. Minarea retiming is a much harder problem than minperiod retiming, and previous techniques where not capable of handling large circuits in a reasonable time. This work de nes the relationship between the Leiserson-Saxe and the ASTRA approaches and utilizes it for e cient minarea retiming of large circuits. The new algorithm, Minaret, uses the same basis as the Leiserson-Saxe approach. The underlying philosophy of the ASTRA approach is incorporated to reduce the number of variables and constraints generated in the problem. This allows minarea retiming of circuits with over 56,000 gates in under fteen minutes.
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