An apparatus for selecting a plurality of input signals from a plurality of y signals in a device has a switching matrix with a plurality of n to 1 mulitplexers, wherein each n to 1 multiplexer is assigned to a different input set of n of the y signals wherein a subset of less than n input signals of each set of input signals of each of the n to 1 multiplexers is also a subset of input signals of another n to 1 multiplexer.