Logic circuit

A circuit for selecting one of a second set of binary inputs according to the number of high input signals applied to a first set of one or more binary inputs, the circuit comprising:

• a first subcircuit having said first set of binary inputs, and logic for generating a set of control output signals, wherein each control output signal represents whether or not the first set of binary inputs has exactly a predetermined number of high input signals, and wherein each control output signal corresponds to a different said predetermined number of high input signals;
• and
• a second subcircuit having said second set of binary inputs, a set of control inputs for receiving control output signals from the first subcircuit, and logic comprising a plurality of switching components including one or more pass gates, each said switching component being switchable to connect or isolate one of the second set of inputs to a common output, wherein the control inputs are connected to control the switching of the switching components to connect only one of said second set of binary inputs to said common output at any one time.