A centrally controlled shuffle network for reconfigurable and fault-tolerant architecture

Abstract

The paper describes a multistage shuffle interconnection network which is controlled by a central monitor. A control code broadcast by the monitor to all the basic switching elements of the network simultaneously, makes the network dynamically reconfigurable. The control code plays three vital roles. Firstly, it establishes conflict-free paths between several source-destination pairs. Thus the problem of collision, a major obstacle of a self-routing network, is completely eliminated. Secondly, the direct paths are established in one clock period irrespective of the number of stages. This makes the system faster. Thirdly, the control code also acts as a grouping code for executing a table of arbitrary data exchange requests between nodes in minimum number of passes. It is also shown that the network can be made fault-tolerant by the addition of an extra stage. Any single fault and some multiple faults in the intermediate stages can be tolerated by this scheme. Moreover, the switching from the faulty state to the fault-free state can be done in a single clock period, thus enabling fast fault-tolerant reconfiguration.