Patent ID: 7623593

Claim:
A data receiving apparatus, comprising: a reference generating means for generating a plurality of reference levels by monitoring a signal level of an inputted data signal or according to an external control command, wherein the reference levels include a typical reference level, a plurality of upward reference levels adjusted higher than the typical reference level, and a plurality of downward reference levels adjusted lower than the typical reference level; a comparing means for comparing the inputted data signal with the reference levels transmitted from the reference generating means and determining a plurality of logic values of the inputted data signal; a selecting means for selecting the logic values of the inputted data signal transmitted from the comparing means as a valid logic value upon a selection control signal; and a selection controlling means for monitoring the valid logic value of the selecting means, transmitting the selection control signal corresponding thereto to the selecting means, and controlling a process for selecting the valid logic value, wherein the comparing means includes: a first comparing unit for determining a typical logic value of the inputted data signal D in by comparing a signal level of the inputted data signal Din with the typical reference level; a plurality of second comparing units for determining a plurality, of upward adjusted logic values by comparing the signal level of the inputted data signal Din with the upward reference levels, individually; and a plurality of third comparing units for determining a plurality of downward adjusted logic values by comparing the signal level of the inputted data signal Din, with the downward reference levels, individually, wherein the selecting means selects any one among the typical logic value of the inputted data signal Din, the upward adjusted logic values, and the downward adjusted logic values, which are transmitted from the comparing means, as the valid logic value of the inputted data signal Din upon the selection control signal from the selection controlling means, and transmits the valid logic value to the selection controlling means, wherein the selection controlling means provides the selection control signal to the selecting means in such a manner that the typical logic value of the inputted data signal Din is selected as the valid logic value of the inputted data signal at first, and then receives a signal from the selecting means, monitors more than two bits of a re-timed valid logic value Dour of the inputted data signal Din according to a rule registered by an external control signal, and provides the selection control signal to the selecting means in such a manner that any one among the typical logic value of the inputted data signal D in , the upward adjusted logic values, and the downward adjusted logic values as a valid logic value of a next data signal.