MISR architectures to remove unknown values in output response compaction

MISR architectures are proposed to remove the unknown (X) values in the output sequences. The MISR signature is represented as a system of linear equations in terms of unknown´s (X). The method of symbolic simulation is used to represent each bit of the MISR signature. The combination of linear equations of the MISR signature bits is determined with Gauss-Jordan Elimination algorithm to remove unknown values in the output responses. These X-cancelled combinations are then computed in a separate storage register to provide X-free combinations values. Experimental result describes that maximum error coverage and test time can be obtained with the help of theses MISR architectures.