A memory-like structure composed of variable resistor elements for use in tuning respective branches and leaves of a clock distribution structure, which may be used to compensate for chip-by-chip and/or combinatorial logic path-by-path delay variations, which may be due, for example, to physical variations in deep submicron devices and interconnections, is presented. A single system clocked scan flip-flop with the capability to perform delay test measurements is also presented. Methods for measuring combinatorial logic path delays to determine the maximum clock frequency and delays to program the variable resistors, as well as methods for calibrating and measuring the programmed variable resistors, are also presented.