Abstract: A system and methods of balancing scan chains and, more particularly, a system and methods of load balancing scan chains into hierarchically designed integrated circuits. The method includes estimating or calculating a maximum scan chain length L and creating a maximum number of scan chains of length L in each hierarchical block. The method further includes distributing remaining scan bits in each hierarchical block into additional scan chains, and creating chip-level scan chains by using the scan chains of maximum length L and by forming additional chip-level scan chains of maximum length L by distributing the additional scan chains of maximum length LR, plus any remaining top-level scan bits, among the additional chip-level scan chains of maximum length L.

Abstract: A system and methods of balancing scan chains and, more particularly, a system and methods of load balancing scan chains into hierarchically designed integrated circuits. The method includes estimating or calculating a maximum scan chain length L and creating a maximum number of scan chains of length L in each hierarchical block. The method further includes distributing remaining scan bits in each hierarchical block into additional scan chains, and creating chip-level scan chains by using the scan chains of maximum length L and by forming additional chip-level scan chains of maximum length L by distributing the additional scan chains of maximum length LR, plus any remaining top-level scan bits, among the additional chip-level scan chains of maximum length L.

Abstract: A boundary scan register circuit and a method of characterization testing. The boundary scan register circuit, including: a multiplicity of boundary scan cells connected in series, each boundary scan cell having a latch; means for isolating the boundary scan cells into one or more boundary scan segments, each boundary scan segment containing a different set of the boundary scan cells; and means for characterizing signal propagation through each boundary scan segment.