A Built-in Self-Reconfigurable Scheme for 3D Mesh Arrays

摘要

We propose a model for fault tolerant 3D pro- cessor arrays using one-and-half track switches. Spare proces- sors are laid on the two opposite surfaces of the 3D array. The fault compensation process is performed by shifting processors on a continuous straight line (called compensation path) from a faulty processor to a spare on the surfaces. It is not allowed that compensantion paths are in the near-miss relation each other [2]. Then, switches with only 4 states are needed to preserve the 3D mesh topology after compensating for faults. We give an algo- rithm in a convenient form for reconfiguring by hardware the 3D mesh arrays with faults. The algorithm can reconfigure the 3D mesh arrays in polynomial time. By computer simulation, we show the survival rates and the reliabilities of arrays which express the efficiencies of reconfiguration according to the algo- rithm. The reliabilities are compared with those of the model using double tracks for which the near-miss relation among com- pensation paths is allowed, but whose hardware overhead is al- most double of that of the proposed model using one-and-half track. Finally, we design a logical circuit for hardware realiza- tion of the algorithm. Using the circuit, we can construct such a built-in self-reconfigurable 3D mesh array that the reconfigura- tion is done very quickly without an aid of a host computer.