Efficient design of totally self-checking checkers for all low-cost arithmetic codes

A method is proposed that is based on the partitioning of the input code variables into two sections, each section representing the binary form of a number Z₁ and Z₂, respectively. For a code with check base A =2^m-1, two m-bit end-around carry adder trees calculate the modulo m residue of Z₁ and Z₂, while a totally self-checking (TSC) translator maps the output of the pair of trees onto m-variable two-rail code. A TSC two-rail checker maps the m-variable two-rail code onto one-out-of-two code. The checkers present significant improvement in the implementation cost, number of gate levels, and reliability over TSC checkers previously proposed in the literature