  In this paper, the Statistical Static Timing Analysis (SSTA) is considered
within the block--based approach. The statistical model of the logic gate delay
propagation is systematically studied and the exact analytical solution is
obtained, which is strongly non-Gaussian. The procedure of handling such
(non-Gaussian) distributions is described and the corresponding algorithm for
the critical path delay is outlined. Finally, the proposed approach is tested
and compared with Monte Carlo simulations.
