Switched deskew on arbitrary data

Abstract

A method and circuit capable of handling skew between a clock and data signal up to +/− one half bit on a random input data pattern. A digital algorithm cycles through each data bit and individually deskews that bit by detecting data transitions in a first sampling region and in a second sampling region and determining a difference between a number of transitions in the first sampling region and a number of transitions in the second sampling region. The sampling regions and a deskew timing signal may then be incremented or decremented based on a comparison of the computed difference to a predetermined constant. If no transitions occur on a particular bit, the algorithm times out leaving the deskew timing signal in the original position. When analysis of a final bit of a channel is completed, the algorithm begins monitoring and analyzing the first bit of another channel.