Skew calibration means and a method of skew calibration

Abstract

A high speed communication apparatus with means for reducing timing uncertainty providing a high accuracy of transferring and receiving signals by intelligent skew calibration of the apparatus. The system for reducing timing uncertainty of a communication apparatus comprises a plurality of driving registers for transmitting signals; a plurality of receiving registers for receiving signals; a main clock for generating a main clock signal; a reference clock for generating reference signals for calibrating the registers; and a plurality of phase shift means comprising at least one set of phase shift means associated with each said plurality of registers, for the relative alignment of the register's timing within each plurality. The apparatus preferably further comprises a storage means for recording and storing information on skew in a communication media, for at least one data pattern transmitted through the transmission line and a plurality of adjustment means for generating and applying a correction to the timing position of a signal transition between two logical levels, the correction being generated on the basis of the information stored in the storage means, so as to compensate the above skew.