A novel design of a combinational network to facilitate fault detection

This letter describes a novel design of a combinational network to facilitate the single stuck-at fault detection problem. The design makes use of EXCLUSIVE-OR modules as control elements and the observability has been increased by providing an additional observable output which is the output of an additional AND gate in the network. Such a design of a combinational network with n primary input variables will require only (n + 1) predefined test input patterns belonging to the set T = {11...11,011...11,101 ...11, ........., 11 ... 110} for the detection of stuck-at single s-a-0 and s-a-1 fault on a line of the network. As a result, the extremely difficult task of test generation can be easily dispensed with.