Multiplexer diagnostic input patterns

In a method for texting a multiplexer, which includes applying binary signals to inputs of said multiplexer, applying binary signals to address lines of said multiplexer in a desired address sequence to select the corresponding one of said binary signals on each of said inputs in a desired input sequence to appear at an output of said multiplexer, said desired input sequence beginning with a first input and ending with a last (Nth) input, assembling each said binary signal at said output during said desired input sequence into an N bit output word, and examining said N bit output word, the step of:

• applying said binary signals to said inputs in a pattern characterized by a reversal of said binary signals at input boundaries defined numerically as radix two raised to successive integer exponents, said interger exponents beginning with zero and increasing positively by one, whereby said N bit output word uniquely identifies one of a number of particular diagnostic conditions of said multiplexer, said conditions including that all of said address lines operate properly, that a specified one of said address lines has a particular fault, that a set of said address lines has one of a number of faults per address line in the set, and that the fault is not diagnosed.