For any oscilloscope there is a time delay between the end of one scan and when the trigger is ready to initiate the next one. During this period the scope does not see any activity that may occur on the signal line For a DSO this time can be relatively long because the scope processes information serially and this can form a bottleneck. However the DPO uses a separate parallel processor and this enables it to capture and store waveforms despite the fact that the display may be acting much slower. By using the parallel processing the DPO is not limited by the speed of the display, signals may be captured independently of the activity of the display.
Although the name of the DPO may indicate that it relies on a chemical phosphor, this is not necessarily the case as more modern displays are used. However it possesses many of the aspects of a phosphor oscilloscope, displaying a more intense image the more often the waveform passes a certain point.
Each time a waveform is captured it is mapped into the DPO memory. Each cell represents a screen location. The more times data is stored into a location, the greater the intensity attached to it. In this way intensity information builds up in cells where the waveform passes most often. The overall