Texas Instruments Corporation

Shaun Lytollis

Simon D Forey

Andrew J Pickering

Robert Simpson

Jesse Jonghyuk Ko

Clock recovery apparatus having an early/late voter for deciding whether a current sampling point needs to be advanced or retarded, wherein the early/late voter passes and Up/Down signal to an interpolator for maintaining a clock signal; a frequency accumulator and rate multiplierfor generating further signals which are summed with those of the Up/Down signal of the early/late voter to provide an improved control signal to the phase interpolator. The accumulator is responsive to frequency changes in the input signal, and the interpolator acts on said Up/Down signals to adjust the clock signal by stepping it forward or backward according to control need, so that the sampling point can be advanced or retarded.

Clock recovery

System and method are implemented to allow phase lock loop (PLL) status testing during a Serializer/Deserializer (SERDES) internal loopback built-in self-test (BIST). An existing pseudo random binary sequence (PRBS) data generator is modified to include a mode that produces a data pattern having a frequency content low enough to be verified on the tester used at the probe.

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Northampton, United Kingdom

Shaun Lytollis