The traditional method based on probabilistic transfer matrices (PTM) enables accurate evaluation of reliability for moderately large combinational circuits

but it can only be applied to combinational circuits.Flip-flop is an important component of sequential circuits

and its reliability estimation is essential for reliability analysis of sequential circuits.Therefore

a general computational framework for reliability estimation of flip-flops based on PTM (F-PTM) and a decision theorem of circuit's PTM are proposed.Firstly

a logical function of the flip-flop circuit is expressed;and then its PTM is calculated by deduction employing the proposed decision theorem;finally

the circuit's reliability is estimated by probability distribution of its inputs.Compared with the traditional PTM method

the F-PTM method can calculate PTMs for both combinational circuits and flip-flop circuits.Experimental results of the classical flip-flop circuits and 74X series circuits show that the F-PTM method is efficient and feasible.The comparison of our method with multiple-pass method and Monte Carlo simulation also demonstrate that the reliability results estimated by the F-PTM method is more accurate.