Abstract: A semiconductor device includes circuitry configured to derive a physical unclonable function. The circuitry includes a plurality of bitcells, each bitcell being readable as one of a ‘0’ value and a ‘1’ value, and sense amplifier circuitry configurable to read values from the plurality of bitcells. The sense amplifier circuitry includes margin circuitry configurable (i) to selectably bias reading of the plurality of bitcells toward one of ‘0’ values and ‘1’ values, (ii) to identify addresses of bitcells having a stable ‘1’ value when the margin circuitry is configured to bias reading of the plurality of bitcells toward ‘0’ values, and (iii) to identify addresses of bitcells having a stable ‘0’ value when the margin circuitry is configured to bias reading of the plurality of bitcells toward ‘1’ values. Each bitcell in the plurality of bitcells may include a differential transistor pair.