A self-testing and self-pruning binary communication tree for a wafer scale database system

The design of the internal node for the WaRP wafer-scale database machine is described. The WaRP architecture consists of a binary tree laid out on a wafer. Most of the data storage and processing occurs in the leaf nodes. The internal nodes of the tree are given the task of distributing queries to the leaves and combining responses. The tree is both fault tolerant and soft-prunable in the field; it is possible to both test the tree and to prune away faulty nodes. As a result, most of the internal node is concerned with testability