Patent ID: 7126513

Claim:
A circuit in an integrated circuit for selecting one of a plurality of digital states in the integrated circuit, the circuit comprising: a first input terminal receiving an input voltage having a first voltage value, the first voltage value being one of a plurality of predetermined programming voltage values comprising voltage levels distributed evenly between a positive power supply voltage and a negative power supply voltage, each predetermined programming voltage value being associated with one of the plurality of digital states; a plurality of comparators, each comparator having a first input terminal coupled to receive the input voltage and a second input terminal coupled to receive a respective reference voltage from a set of reference voltages, each reference voltage from the set having a voltage value midway between a pair of adjacent voltage values in the plurality of predetermined programming voltage values, the plurality of comparators providing a plurality of comparison output signals indicating the detected voltage value of the input voltage; and a control circuit coupled to receive the plurality of comparison output signals and to generate an output control signal for selecting one of the plurality of digital states based on the plurality of comparison output signals.