Patent ID: 8693125
Filing Date: 2014-04-08
Classification: G11B

Abstract:
1. A data processing apparatus, comprising: a signal path configured to carry an analog data signal; a selector circuit operable to inject one of a first analog clock signal or a second analog clock signal into the signal path, the selector circuit configured to replace the data signal with the injected one of the first analog clock signal or the second analog clock signal on the signal path; an analog to digital converter configured to convert the injected one of the first analog clock signal or the second analog clock signal to a digital clock signal; a counter configured to select a time, using at least one of the first analog clock signal or the second analog clock signal, to determine at least one of a phase or a magnitude of the digital clock signal; and a measurement circuit configured to determine at least one of the phase or the magnitude of the digital clock signal for at least one frequency at the selected time.