High-speed serial data transceiver and related methods
A high-speed serial data transceiver includes multiple receivers and transmitters for receiving and transmitting multiple analog, serial data signals at multi-gigabit-per-second data rates. Each receiver includes a timing recovery system for tracking a phase and a frequency of the serial data signal associated with the receiver. The timing recovery system includes a phase interpolator responsive to phase control signals and a set of reference signals having different predetermined phases. The phase interpolator derives a sampling signal, having an interpolated phase, to sample the serial data signal. The timing recovery system in each receiver independently phase-aligns and frequency synchronizes the sampling signal to the serial data signal associated with the receiver. A receiver can include multiple paths for sampling a received, serial data signal in accordance with multiple time-staggered sampling signals, each having an interpolated phase.
1. A method for sampling a high data rate signal for a communication device, comprising:
sampling a received serial data signal using a plurality of time-staggered sampling signals to generate a plurality of time-staggered sampled signals;
detecting time offsets between the plurality of time-staggered sampled signals, the time offsets representing differences between respective time-staggered sampling signals and the received serial data signal; and
adjusting the plurality of time-staggered sampling signals based on the time offsets.
2. The method of claim 1 , further comprising:
time-deskewing the plurality of time-staggered sampled signals to generate a plurality of time-deskewed sampled signals.
3. The method of claim 2 , further comprising:
generating a parallel signal from the plurality of time-deskewed sampled signals, wherein the parallel signal includes samples of the received serial data signal.
4. The method of claim 1 , wherein adjusting the plurality of time-staggered sampling signals comprises:
adjusting the plurality of time-staggered sampling signals such that each of the plurality of time-staggered sampling, signals has an interpolated phase.
5. The method of claim 1 , wherein adjusting the plurality of time-staggered sampling signals comprises:
adjusting the plurality of time-staggered sampling signals based on a timing signal;
generating a set of reference signals having different phases from the timing signal;
generating a second timing signal having an interpolated phase from the set of reference signals; and
adjusting the plurality of time-staggered sampling signals based on the second timing signal, wherein each of the plurality of time-staggered sampling signals has an interpolated phase related to the interpolated phase of the second timing signal.
6. The method of claim 1 , wherein the sampling of the received serial data signal comprises:
sampling the received serial data signal at a plurality of sampling times, each of the plurality of sampling times corresponding to a respective one of the plurality of time-staggered sampling signals.
7. A communication device, comprising:
a sampler that comprises a plurality of sampling paths, the plurality of sampling paths being configured to sample a received serial data signal using a corresponding one of a plurality of time-staggered sampling signals, thereby generating a plurality of time-staggered sampled signals;
a time-deskewer coupled to the sampler, wherein the time-deskewer is configured to remove time offsets between the plurality of time-staggered sampled signals, the time offsets representing differences between respective time-staggered sampling signals and the received serial data signal; and
a sampling signal generator coupled to the time-deskewer, wherein the sampling signal generator is configured to adjust the plurality of time-staggered sampling signals based on the time offsets.
8. The communication device of claim 7 , wherein the time-deskewer is configured to time-deskew the plurality of time-staggered sampled signals to generate a plurality of time-deskewed sampled signals, wherein the plurality of time-deskewed sampling signals are characterized as having approximately zero time offset relative to one another.
9. The communication device of claim 8 , further comprising:
a deserializer configured to generate a parallel signal from the plurality of time-deskewed sampled signals, wherein the parallel signal includes samples of the received serial data signal.
10. The communication device of claim 7 , wherein the sampling signal generator is further configured to generate the plurality of time-staggered sampling signals based on a timing signal, and wherein the sampling signal generator comprises:
a signal generator configured to generate a set of reference signals having different phases from the timing signal; and
a phase interpolator module configured to generate a second timing signal having an interpolated phase from the set of reference signals and to adjust the plurality of time-staggered sampling, signals from the second timing signal, wherein each of the plurality of time-staggered sampling signals has an interpolated phase related to the interpolated phase of the second timing signal.
11. The communication device of claim 7 , wherein each of the plurality of sampling paths comprises:
a quantizer configured to quantize a corresponding one of the plurality of time-staggered sampled signals.
12. The communication device of claim 7 , wherein the sampling signal generator comprises:
a first signal set generator, wherein the first signal set generator is configured to generate a set of reference signals having different predetermined phases;
an interpolator module coupled to the first signal set generator, wherein the interpolator module is configured to generate a plurality of interpolated timing signals based on the set of reference signals and a plurality of phase control signals; and
a second signal set generator coupled to the interpolator module, wherein the second signal set generator is configured to adjust the plurality of time-staggered sampling signals based on the plurality of interpolated timing signals.
13. A sampling signal generator, comprising:
a first signal set generator, wherein the first signal set generator is configured to generate a set of reference signals having different predetermined phases;
an interpolator module coupled to the first signal set generator, wherein the interpolator module is configured to generate a plurality of interpolated timing signals based on the set of reference signals and a plurality of phase control signals; and
a second signal set generator coupled to the interpolator module, wherein the second signal set generator is configured to:
generate a plurality of time-staggered sampling signals based on the plurality of interpolated timing signals, and
adjust the plurality of time-staggered sampling signals based on a plurality of time offsets, the plurality of time offsets representing differences between respective time-staggered sampling signals and a received serial data signal.
14. The sampling signal generator of claim 13 , wherein the interpolator module is further configured to receive the plurality of phase control signals from an interpolator control module coupled to the interpolator module.
15. The sampling signal generator of claim 13 , wherein the second signal set generator is configured to adjust the plurality of time-staggered sampling signals based on the plurality of interpolated timing signals.
16. The sampling signal generator of claim 13 , wherein the first signal set generator is further configured to:
receive a master timing signal; and
generate the set of reference signals based on the master timing signal.
17. A method for sampling a high data rate signal for a communication device, comprising:
generating a set of reference signals having different predetermined phases;
generating a plurality of interpolated timing signals based on the set of reference signals and a plurality of phase control signals;
generating a plurality of time-staggered sampling signals based on the pluralty of interpolated timing signals; and
adjusting the plurality of time-staggered sampling signals based on a plurality of time offsets, the plurality of time offsets representing differences between respective time-staggered sampling signals and a received serial data signal.
18. The method of claim 17 , further comprising:
receiving the plurality of phase control signals from an interpolator control module.
19. The method of claim 17 , further comprising:
adjusting the plurality of time-staggered sampling signals based on the plurality of interpolated timing signals.
20. The method of claim 17 , further comprising:
receiving a master timing signal; and
generating the set of reference signals based on the master timing signal.