Control loop management and differential delay correction for vector signaling code communications links

摘要

Vector signaling code communications systems rely on group transmission of code symbols using multiple signaling channels that may have differing propagation characteristics, resulting in differing received signal levels, waveforms, and symbol arrival times, and thus that should be actively monitored and adjusted to minimize differential signal characteristics. Information obtained during symbol decode may be analyzed to identify channel operational characteristics during normal operation and perform non-disruptive channel adjustments, including per-channel adjustment of sample-and-hold timing to realign code symbol groups. Initialization or start-up adjustment may also be performed using intentionally-transmitted training patterns.

主权项

1. In a device that communicates over a communications interface having a plurality of channels with communications according to a vector signaling code, a method of adjusting and controlling the communications interface comprising:
measuring a signal level of each of a measured plurality of the channels; comparing signal levels between a first set of pairs of the measured plurality of the channels to form a first set of comparisons; comparing signal levels between a second set of pairs of the measured plurality of the channels, wherein the second set is not identical to the first set, to form a second set of comparisons; reading data that maps data patterns of the first set of comparisons and the second set of comparisons to corresponding identified secondary communication characteristics, such that a data pattern is deemed likely to be sensitive to its corresponding identified secondary communication characteristic; identifying at least one data pattern and its corresponding identified secondary communication characteristic; determining a metric for the identified secondary communications characteristic using signal levels associated with its corresponding data pattern; and outputting one or more instructions that, when received, would cause the communications interface to adjust the identified secondary communications characteristic.