Patent ID: 7542862
Filing Date: 2009-06-02
Classification: G01R

Abstract:
1. A method for determining at least one coefficient relating a delay of a delay circuit to a value of a circuit metric under measurement, the method comprising: fixing an environment of the delay circuit so that the circuit metric has a fixed value; measuring the delay of the delay circuit by a delay measurement circuit; determining from a predetermined relationship expected between the delay of the delay circuit and a position within a process distribution for the circuit, at least one coefficient relating the delay of the delay circuit to the value of the circuit metric; and storing the at least one coefficient in an electronically-accessible storage location, whereby subsequent delay measurements of the delay circuit are corrected for the process variation using the at least one coefficient, wherein the fixing fixes a temperature of the delay circuit and a voltage of the delay circuit, and wherein the determining determines the position of the delay circuit within a predetermined distribution of delays corresponding to the process distribution, and determining the at least one coefficient in conformity with the position of the delay circuit within the predetermined distribution of delay differences.