Deterministic Specification and Field-Extensibility: A Methodology for Long-Life Digital Logic Synthesis

We present a chip-design methodology that specifies every inputcombination of a Boolean function explicitly at design time -without don't-care assignments - and reserves a portion of theinput address space for future function additions. Afterdeployment, NEW Boolean functions may be added to the fieldedsilicon WITHOUT modifying or re-synthesizing the original logic,by synthesizing additional fixed-logic blocks that wire to thesame inputs and combine via an OR gate or designer-selectablemultiplexer. The methodology eliminates the re-synthesis,re-spin, and re-certification costs that conventional don't-care-based synthesis incurs when a previously "don't-care" inputcombination later becomes meaningful. Particularly applicable tosafety-certified industries (avionics DO-178C, automotive ISO26262, medical FDA Class III, industrial control IEC 62443)where re-certification of an updated chip can cost $1M-$20M. Wedescribe the methodology, the algebraic properties of itscomposition operation, the audit-trail requirements, andconcrete worked examples in five regulated industries. Companionto the foundational M-Maps paper (DOI 10.5281/zenodo.20498821),the structural-atom engine paper (DOI 10.5281/zenodo.20499264),and the hierarchical scaling paper (DOI 10.5281/zenodo.20499525).