A novel architecture of an SRAM-based Physical Unclonable Function (PUF) whose unstable cells are identified and masked by a “capacitive-tilt” preselection test is proposed. During the preselection test, either one of the cross-coupled inverter nodes is loaded with a digitally controlled capacitance, which can tilt the PUF towards a “1” or a "0". Any cell which maintains its value during this test is deemed stable. In a test-chip implementation in 65nm, the preselection test identified and disqualified all the unstable. An overall scheme for PUF stabilization is proposed, composed of two error-reductions steps, comprising Inner and Outer error control blocks.