Monitoring and control of reference clocks to reduce bit error ratio

A non-transitory computer readable medium (CRM) comprising instructions stored thereon for reducing a frequency error, the instructions when executed by a processor causes the processor to:

• apply a plurality of dither values to a local reference clock over a first time interval by:
• applying, by modifying a divider, a first set of positive dither values during a first half of the first time interval, and
• applying, by modifying the divider, a second set of negative dither values during a second half of the first time interval;
• track a plurality of bit errors from sampling a first plurality of data values received over an asynchronous link,
• wherein the first plurality of data values are sampled during the first time interval using the local clock reference, and
• wherein the first plurality of data values are transmitted over the asynchronous link based on a remote reference clock;
• and
• adjust, based on the plurality of bit errors, a frequency of the local reference clock to reduce the frequency error between the local reference clock and the remote reference clock.

A system for reducing a frequency error, comprising:

• a local reference clock comprising a divider;
• a clock and data recovery (CDR) circuit configured to sample, using the local reference clock, a plurality of data values during a first time interval, wherein the first plurality of data values are received over an asynchronous link, and wherein the first plurality of data values are transmitted over the asynchronous link based on a remote reference clock;
• and
• an error monitoring and frequency control (EMFC) circuit configured to:
• apply a plurality of dither values to the local reference clock over the first time interval by:
• applying, by modifying the divider, a first set of positive dither values during a first half of the first time interval, and
• applying, by modifying the divider, a second set of negative dither values during a second half of the first time interval,
• track a plurality of bit errors from the sampling of the first plurality of data values, and
• adjust, based on the plurality of bit errors, a frequency of the local reference clock to reduce the frequency error between the local reference clock and the remote reference clock.