Partially duplicated code-disjoint carry-skip adder

In this paper a new self-checking code-disjoint partially duplicated fast carry-skip adder is proposed which is for 64 bits the fastest self-checking adder known so far. For the first time the adder cells of a fast carry-ripple adder are used for the design of a carry-skip adder. The propagate signals are implemented only once. They are utilized to compute the duplicated sum bits and simultaneously to check the input parity and some internal XOR-gates.