A Cost Analysis Framework for Multi-core Systems with Spares

It becomes increasingly difficult to achieve a high manufacturing yield for multi-core chips due to larger chip sizes, higher device densities, and greater failure rates. By adding a limited number of spare cores to replace defective cores either before shipment or in the field, the effective yield of the chip and its overall cost can be significantly improved. In this paper, we propose a yield and cost analysis framework to better understand the dependency of a multi-core chip´s cost on key parameters such as the number of cores and spares, core yield, and defect coverage of manufacturing and in-field testing. Our analysis shows that we can eliminate the burn-in process when we have some spare cores for in-field recovery. We demonstrate that a high defect coverage for in-field testing, a necessity for supporting in-field recovery, is essential for overall cost reduction. We also illustrate that, with in-field recovery capability, the reliance on high quality manufacturing testing is significantly reduced.