Patent ID: 7863928

Claim:
A data line termination circuit comprising: a swing-width sensing unit configured to sense a swing width of a voltage of a data line and to output a sensed signal according to the sensed swing width; and a variable termination unit configured to adjust a termination resistance value of the data line according to the sensed signal, wherein the variable termination unit comprises: a first termination unit configured to set a resistance value of the data line to a first termination resistance value according to the sensed signal; and a second termination unit configured to set the resistance value of the data line to a second termination resistance value according to the sensed signal; wherein the swing-width sensing unit is configured to compare the voltage of the data line with each of a plurality of reference voltages and to output the sensed signal having a logic level that is a first logic level or a second logic level, wherein the logic level is determined based upon whether the results of the comparison of each of the plurality of reference voltages with the voltage of the data line are the same, wherein the swing-width sensing unit comprises: a first comparator configured to compare the voltage of the data line with a first reference voltage; a second comparator configured to compare the voltage of the data line with a second reference voltage; a third comparator configured to compare the voltage of the data line with a third reference voltage; and an encoder configured to encode outputs of the first to third comparators in order to output the sensed signal, wherein the encoder is configured to output the sensed signal such that the logic level is the first logic level if the outputs of each of the first to third comparators have the same logic levels, and configured to output the sensed signal having the second logic level if the outputs of the first to third comparators all do not have the same logic level.