Configurable protocol decoders for Manchester and NRZ coding added to scopes

April 17, 2013 // By Graham Prophet
LeCroy - now Teledyne LeCroy - has announced Manchester and NRZ (non-return-to-zero) configurable protocol decoders for a wide range of oscilloscope platforms. The decoders enable users to specify a broad range of physical layer characteristics for Manchester- or NRZ-encoded signals.

The decoders define the grouping of bits into words, and words into frames, which simplifies analysis for custom and/or proprietary protocols based on those generic encoding schemes. Decoded information is then shown in a colour-coded overlay directly on top of the physical layer waveform.

Many of today’s data-communication protocols are built on Manchester or NRZ encoding. Protocols like this range from specialised buses such as Digital Addressable Lighting Interface (DALI) for control of building lighting and the Peripheral Sensor Interface 5 (PSI5) used to connect sensors to controllers in automotive applications, to proprietary, custom buses used for non-standardised applications. In all of these cases, basic Manchester and NRZ schemes are modified to create the more complex, specialised protocols. Designersare developing and debugging systems with these protocols and looking for bus analysis tools to simplify the process.

Teledyne LeCroy’s Manchester and NRZ protocol provide broad flexibility in terms of physical layer characteristics, protocol word and frame structure as well as other parameters. Users may specify bit rates from 10 bits/s to 10 Gbits/s. Idle states, sync bits, header and footer information can all be configured to decode custom preambles or CRC details. Decoding is highly flexible: data mode can be in bits or words; viewing in hex, ASCII, or decimal; and bit order may be either LSB or MSB. Decoded information is displayed with a colour-coded overlay which expands or contracts as the user adjusts the oscilloscope timebase or zooms in on the waveform for more details.

Powerful search capabilities allow users to quickly search long captures of decoded Manchester and NRZ waveforms for specific bus details such as data, sync or inter-frame gap. Decoded data is displayed in an interactive table. Clicking on any line in the table opens a zoomed view of that instance in the waveform.