Efficient Exact Spare Allocation via Boolean Satisfiability

Fabricating large memory and processor arrays is subject to physical failures resulting in yield degradation. The strategy of incorporating spare rows and columns to obtain reasonable production yields was first proposed in the 1970s, and continues to serve as an important role in recent VLSI developments. Since the spare allocation problem (SAP) is NPcomplete but requires solving during fabrication, an efficient exact spare allocation algorithm has great value. Here we propose a new Boolean encoding of SAP and a new SATbased exact algorithm SATRepair. We used a realistic fault distribution model to compare SATRepair’s performances against BDDRepair and those of algorithms found in the literature. We suggest that a) our novel Boolean encoding of SAP allows for the development of efficient exact SAP algorithms, and b) our SAT-based algorithm outperforms previous algorithms, especially for large problems.

• Type: Conference
• Year: 2005
• Where: DFT
• Authors: Fang Yu, Chung-Hung Tsai, Yao-Wen Huang, D. T. Lee, Hung-Yau Lin, Sy-Yen Kuo
• Keywords: Boolean Encoding, DFT 2005, Exact Spare Allocation, Hardware, Spare Allocation