Patent ID: 6864721

Claim:
A decode circuit for selecting one of a plurality of output lines in dependence on the status of a plurality of input lines, the circuit comprising: a first decode node; first precharging circuitry for charging the first decode node to a charging potential; first discharging circuitry comprising a plurality of switching means each operable in dependence on the status of a respective one of the input lines to couple the first decode node to a discharging potential; and first selection circuitry coupled to a respective one of the output lines and operable in response to a first enable signal to select that output line if the first decode node has not discharged; and a second decode arrangement comprising: a second decode node; second precharging circuitry for charging the second decode node to a charging potential; second discharging circuitry comprising a plurality of switching means each operable in dependence on the status of a respective one of the input lines to couple the second decode node to a discharging potential; and second selection circuitry coupled to a respective one of the output lines and operable in response to a second enable signal to select that output line if the second discharge node has not discharged; wherein the first enable signal is derived from the potential of the second decode node.