Design of self-testing checkers for Borden codes

The optimal codes C(n,t) capable of detecting t-unidirectional errors in an n-bit vector were defined by Borden (1982). Unidirectional errors have been observed in modern digital devices such as PLAs, ROMs, and compact laser disks. In this paper, a new approach to designing self-testing checkers (STCs) for Borden codes is proposed. The new STC is built of a self-testing code-disjoint translator of the Borden code into the 1-out-of-z code (z⩾2) and if z=3 or 4 an STC for the 1-out-of-n code. The translator is built of two multi-output threshold circuits with [n/2] and [n/2] inputs and a merging network. Compared to existing STCs for Borden codes the new checker generally uses significantly less hardware. It also enjoys a modular and highly regular structure which makes it attractive for VLSI implementation