A list of waveforms is received (the list being one that is to be driven to or received from a pin of a device under test). The list of waveforms is de-interleaved to form lists of non-interleaved waveforms. Each list of non-interleaved waveforms is then optimized by combining at least two of its entries. By way of example, the above method may be implemented by program code stored on a number of computer readable media, or by a circuit tester having program code for implementing same.