On-chip bathtub BER measurement for high-speed serdes diagnostics

摘要

A method for evaluating operation of a receiver comprising an analog front end, a plurality of samplers connected in parallel to the analog front end, the plurality of samplers comprising a plurality of utility samplers, a plurality of data samplers and a plurality of timing samplers, an unrolled decision feedback equalizer (UDFE) connected to outputs of the plurality of data samplers, and a serial input parallel out (SIPO) block connected to an output of the UDFE and outputs of the plurality of utility and timing samplers. The method comprises adjusting settings of the plurality of utility samplers to sweep across a range of interest, at each of a plurality of points comparing a selected output of one of the plurality of utility samplers at that point to an output of one of the plurality of data samplers to detect an error event, and, accumulating the error events.

主权项

1. A method for evaluating operation of a receiver, the receiver including: an analog front end for receiving a serial input signal and generating a pre-processed signal; a plurality of samplers connected in parallel to the analog front end for sampling the pre-processed signal, the plurality of samplers comprising a plurality of utility samplers, a plurality of data samplers and a plurality of timing samplers; an unrolled decision feedback equalizer (UDFE) connected to outputs of the plurality of data samplers; and a serial input parallel out (SIPO) block connected to an output of the UDFE and outputs of the plurality of utility samplers and the plurality of timing samplers for generating a parallel output signal, the method comprising:
adjusting settings of the plurality of utility samplers to sweep across a range of interest, where a number of utility samplers swept across the range of interest is equal to a number of the plurality of data samplers; at each of a plurality of points spanning the range of interest, comparing a selected output of one of the plurality of utility samplers at that point to an output of one of the plurality of data samplers to detect an error event; and, accumulating the error events for the plurality of points spanning the range of interest.