Enhanced self-configurability and yield in multicore grids

As we move deeper in the nanotechnology era, computer architecture is solicited to manipulate tremendous numbers of devices per chip with high defect densities. These trends provide new computing opportunities but efficiently exploiting them will require a shift towards novel, highly parallel architectures. Fault tolerant mechanisms will have to be integrated to the design to deal with the low yield of future nanofabrication processes. In this paper we consider multi processor grid (MPG) architectures that assure scalability beyond hundreds of cores per chip. We study self-diagnosis and self-configuration methods at the architectural level and propose an enhanced self-configuration methodology that enables usage of a maximum percentage of available fault-free cores in MPGs with high defect densities. We show that our approach achieves usability of all fault-free cores for the case of fault-free routers whereas previous work was efficient for defect densities of up to 20-25% of defective cores. We also address the case of faulty routers, achieving usability of almost all fault-free nodes (fault-free cores having a fault-free router) for very high defect densities both in the cores and in the routers.