Testing the CXPI bus with R&S oscilloscopes

September 28, 2016 // By Christoph Hammerschmidt
The CXPI bus is a new, cost-effective alternative to the LIN bus for low-end automotive applications. With a new software option for its RTE and RTO oscilloscope families, measurement instrument provider Rohde & Schwarz it becomes possible to test CXPI interfaces already during the development process.

The option includes the ability to analyze serial triggering and decoding schemes. In addition, users can decode all protocol details and isolate anomalies by triggering to protocol details, helping designers to verify and commission CXPI interfaces faster.


CXPI (Clock Extension Peripheral Interface) has been created in 2015 as a commuincations bus for several automotive applications under the rules of the SAE J3706 standard. The bus works with pulse width modulation across a single wire and features a data transfer rate of 20 kbit/s. The characters used are based on UART.

For debugging in development environments, users can trigger to CXPI instructions such as Start of Frame, specific data patterns or various error states. The search and navigation function of the option helps users to identify relevant events in the CXPI data stream. The oscilloscopes display the decoded telegrams as color-coded bus signals in the measurement diagram or in a table.

Rohde & Schwarz’ option enables RTE and RSE oscilloscopes to monitor up to four serial buses synonymously.

More information: www.rohde-schwarz.com/ad/press/rto-k76.