This invention describes a method of synchronizing test clocks in an LSSD
system to achieve near simultaneous arrival of the clock signals at the
inputs of all LSSD registers. The method relies on pipelining the latches
to distribute the test clocks, where all pipeline latches are
synchronized by the system clock. This enhancement improves the frequency
at which the test clocks switch and improve the testing throughput by
reducing testing time, resulting in significant reductions in testing
hardware and overall time required for system test, without compromising
any of the benefits associated with conventional LSSD techniques. The
method further enhances the distribution of the test clock signals to
points throughout the entire chip, with a distribution network that is
tailored according to a desired LBIST speed.