I am using the  Beagle I2C/SPI Protocol Analyzer with a PKSA for probing a temperature sensor. I have two questions about viewing and interpreting the captured data.

Here is a temperature reading and an ID read from the PKSA and the decoded results using the Beagle I2C/SPI analyzer with Data Center Software. Is there a way to see or interpret the details of the scope captured data?

PKSA Reading

Data Center Software Output

According to the Beagle Protocol Analyzer User Manual, there is a section about “Timing Mode”, but I don’t see how to activate it. How can I get the timing mode to display waveforms?

Thanks for your questions! The output that you provided, Data Center Software Output, reflects the captured data – we will provide details to help you understand the information that is displayed. We will then show you how to easily view the data in digital waveforms.

About the Scope Data

Each byte of the transaction appears as a row in this pane. All the bytes from the transaction are displayed in this pane, including start and stop conditions. The first line of the table displays the transaction timestamp as well as the transaction duration. The precision of the timestamp and the transaction is 20 nanoseconds.

Each row contains the following information:

• Offset: The offset position of the byte.
• Time: The time in nanoseconds from the start of the transaction to the start of the byte.
• Value: The hexadecimal value of the byte.
• Timing: A graphical display of each individual bit of a byte.

  • Each bit is displayed as being either high or low with the time in nanoseconds from the start of the current bit to the start of the subsequent bit. The lengths of the timing blocks in the graph are not drawn to scale; they provide a reference to the relative time scale of one-bit time to the next.
  • For the I2C protocol, the timing mode displays 9 bits per line. The ninth bit is the ACK/NACK bit. Please note - depending on the protocol, the bit order may be MSB or LSB. You can determine the bit order by looking at the column label. The text in the label indicates if the data is MSB, shown as (b7...b0) or LSB, shown as (b0...b7). Looking at Data Center Software Output, the data is MSB: Timing (ns): [b7..b0 + ACK]
  • (In the case of the SPI protocol, the timing mode displays both MOSI and MISO data.)

Timing Mode for Waveform View

In the Data Center Software, the Timing option of the Details window provides bit-level timing for the data of I2C (and SPI) transactions. This feature is available under Timing Details (select Timing in the Details window). The Details window displays the lower-level detailed information about a specific transaction. An example is shown below.

Data Center Software - Timing of Captured Data

We hope this answers your questions. Additional resources that you may find helpful include the following:

• Beagle Protocol Analyzer User Manual
• Data Center Software User Manual

If you want more information, feel free to contact us with your questions, or request a demo that applies to your application.