Whether USB or CAN Bus decoding confirming that data is being transmitted correctly between the modules connected to each other by serial bus, and that the data content is as intended, is a part of developing and maintaining any system using serial buses for data communication via a serial peripheral interface; over distances as small as a few millimeters for PCIe interconnects on computer boards, up to the 1700 meters possible with 10BASE-T1L Ethernet for factory automation,
As the data communication is a series of events, oscilloscopes are best suited to investigating serial buses, primarily in the time domain. Both for debug and maintenance, two basic functions based on the protocol rules defined for a standard are required:
- Trigger (and search) on protocol events
The oscilloscope shall acquire the waveforms resulting from a selected bus event such as the start of a frame, frame ID, specified data content, or error conditions. Being able to use search functions to locate the part of the acquired waveform containing the trigger event quickly, greatly speeds any analysis. - Decode data
Decode the binary values used to transmit data via a serial bus into a suitable protocol level for a man or machine to understand, such as alpha-numeric characters for plain text or hexadecimal values (for example) depending on the bus application.
