Abstract: A test system having a feedback loop that facilitates adjusting an output test waveform to a DUT/CUT (Device Under Test/Circuit Under Test) on-the-fly according to changing DUT/CUT parameters. The system includes a tester having an arbitrary waveform generator (AWG) and a data acquisition system (DAS) that monitors the status of the DUT/CUT. The AWG and DAS connect to the DUT/CUT through a feedback loop where the AWG outputs the test waveform to the DUT/CUT, the DAS monitors the DUT/CUT parameters, and the DAS analyzes and communicates changes to the AWG to effect changes in the output waveform, when desired. The AWG builds the output waveform in small slices (or segments) that are assembled together through a process of selection and calibration. The feedback architecture facilitates a number of changes in the output waveform, including a change in the original order of the preassembled slices, and changes in the magnitude/shape of the output waveform.