Typically, commercially available standard-cell libraries consist of a large set of items, including cells optimized with respect to speed, area or power consumption. A large number of cells makes the synthesis process and the library maintenance quite demanding. By using a reduced set of properly-selected cells, such efforts can be reduced, without critically affecting performance. This paper introduces an innovative library-reduction strategy, based on a evolutionary algorithm, which allows for selecting an arbitrarily small subset of cells. Library compaction is strictly related to the features of the actual synthesis tool, and is tuned by means of a large set of benchmark circuits, so that it produces results suitable for general-purpose circuit design. Different technologies were accounted for, analyzing dependence of the area, time and power figures on the library cell count. Performance, with respect to full-size library synthesis, do not appreciably degrades, and in several cases actually improves. Synthesis time decreases and library maintenance and characterization tasks can thus be significantly reduced.
['Andrea Ricci', 'Ilaria De Munari', 'Paolo Ciampolini']
An evolutionary approach for standard-cell library reduction