Using Oscilloscope Segmented Memory for Serial Bus Applications

Application Notes

If the signals that you need to capture on an oscilloscope have relatively long idle times between low duty cycle pulses or bursts of signal activity, such as packetized serial data, then using a scope with segmented memory acquisition can effectively extend the amount of time and the number of serial packets that can be captured at a higher sample rate.

All oscilloscopes have a limited amount of acquisition memory. And you should be aware that a scope’s memory depth determines the amount of waveform time and the number of serial packets the scope can capture at a particular sample rate. Although you can easily set a scope’s timebase to a very slow time/div setting in order to capture very long time-spans and lots of serial packets, scopes will automatically reduce their sample rates once the maximum time-span at the scope’s maximum sample rate has been exceeded. When a scope’s sample rate is reduced, it can no longer provide precision horizontal and vertical waveform detail (based on the scope’s specified bandwidth and maximum sample rate).