Although there are already a number of established methods and guidelines, which have proven their usefulness for the development and verification of high integrity software employed for the control of safety related technical processes, these measures cannot ultimately guarantee the correctness of larger programs with mathematical rigour, yet, and, hence, corresponding safety licences are generally denied. As a remedy for this unsatisfactory situation, a novel approach based on the utilisation of programmable gate arrays is presented. The hard-wired discrete logic built of relays or LSI/MSI-chips, which operates in many safety related control systems in parallel to computers, is replaced by programmable logic constructed from PGAs. Thus, the flexibility of programmable electronic systems is combined with the long established and generally accepted rigorous certify ability of hardwired sequential circuits, since in both cases the same design and verification procedures are employed. A PGA is programmed to perform certain Boolean or sequential functions by loading appropriate bit patterns into internal static memory cells. A method for the verification of their contents is detailed, which is based on diverse backward analysis and which can easily be automated. The utilisation of PGAs is not only advantageous for re-placing hard-wired by programmable logic, but also as a novel means of providing diverse redundancy in programmable electronic systems comprising computers and programmable logic controllers.