Patent Document ID: 20150100839
Application ID: 14047869
Patent Flag: 0

Claim One:
1. A generalized modular redundancy fault tolerance method for a combinational circuit, comprising the steps of: setting a protection threshold thr for identifying dominant combinations at the outputs of the combinational circuit, wherein a combination S is dominant if probability of occurrence for the combination S is greater than the threshold thr; generating a truth table of the combinational circuit; for each output i of the combinational circuit, calculating probability of occurrence P i (0), P i (1), based on the truth table; for all remaining outputs j calculating probability of occurrence P ij (00), P ij (01), P ij (10), P ij (11) based on the truth table; choosing a best candidate j where thr has been met with minimum N P ij ; synthesizing a single protection correction circuit operable with the combinational circuit when decision criteria P(D i )>thr and N P ij >2 are met; synthesizing a single protection correction circuit operable with the combinational circuit when decision criteria P(D i )>thr and N P ij ≦2 and P(D i )≧P(D ij ) are met; synthesizing a pair protection correction circuit operable with the combinational circuit when decision criteria P(D i )>thr and N P ij ≦2 and P(D i )<P(D ij ) are met; synthesizing a pair protection correction circuit operable with the combinational circuit when decision criterion P (D i )>thr is not met and when decision criterion N P ij ≦3 is met; synthesizing a triple modular redundancy (TMR) protection correction circuit operable with the combinational circuit when decision criteria for single and pair protection have not been met; and wherein P(D i ) is the probability of occurrence for the dominant combination at output i, P(D ij ) is the probability of occurrence for the dominant combination(s) at paired outputs i,j, P i is the probability of occurrence of a combination S at output i, P ij is the probability of occurrence of combination S when pairing outputs i,j, and N P ij is the number of protected combinations when pairing outputs i,j and the protection correction circuits provide fault protected outputs, ensuring minimum Hamming distance of 3 between the protected combinations and minimum Hamming distance of 1 between the protected combinations and their respective faulty combinations.