A method, apparatus and computer program product are provided implementing
a scan chain diagnostics technique. The diagnostics technique includes
employing fuses coupled to latches of the scan chain to load a known
logic value into the latches at known locations of the scan chain, and
then unloading values from the scan chain, and if the scan chain is
defective (for example, based on the unloaded logic values), then
localizing a defect in the scan chain from the unloaded logic values by
comparison thereof with the known locations of the latches of the scan
chain loaded with the known logic value via the fuses. The scan chain may
be predesigned with fuses spaced periodically across the chain every n
latches to facilitate subsequent localization of a detected defect in the
scan chain.