Patent ID: 8847777

Claim:
An apparatus comprising: a delay unit coupled to receive a signal and configured to output a delayed complement of the signal; a calibration unit configured to, when operating in a first mode, determine an amount of delay provided by the delay unit; a comparison unit coupled to receive the signal and the delayed complement of the signal, wherein the comparison unit is configured to, when operating in a second mode, compare a complement of the signal to the delayed complement of the signal, and wherein the comparison unit is further configured to generate an error indication if a logic level of the complement of the signal does not match a logic level of the delayed complement of the signal; and a control unit configured to enable the calibration unit when operating in the first mode and further configured to disable the calibration unit when operating in the second mode, and wherein the control unit is further configured to adjust an amount of delay provided by the delay unit when operating in the first mode.