Restructuring WSI hexagonal processor arrays

Fault-tolerant approaches have been widcly em­ ployed to improve the yield of ULSI and WSI processor arrays. In this paper, we propose a host-driven reconfiguration scheme, called HEX-REPAIR, for hexagonal processor arrays charac­ terized by a large number of relatively simple cells. Such arrays have heen shown to be the most efficient for many digital signal processing applications, such as matrix multiplication, and for some classes of filtering operations. Reconfiguration for these arrays is made difficult by the asymmetric nature of the inter­ connection network and the need for keeping the switching overheads at a minimum. The algorithm presented in this pa­ per meets these requirements. In addition, it has excellent fault­ coverage characteristics, even in the presence of multiple faults, and can accommodate multiple rows/columns of spare cells. The restructured array is transparent to users and no modification is required in any application program using the array.