SPI Protocol Analysis up to 40 MHz using Promira Serial Platform

Photo by Arturo Anez via Pexels

Effective development and debugging of high-speed SPI systems depends on real-time visibility into bus activity. The Promira® Serial Platform with Data Center Software provides detailed real-time insights into SPI communication up to 40 MHz as it occurs.

The Promira Serial Platform is a high-performance, FPGA-based serial communication device built to adapt to evolving embedded development needs. It can function as an I2C or SPI host adapter, or an I2C, SPI, or eSPI protocol analyzer. Its field-upgradeable design allows engineers to easily expand functionality through configurable applications, unlocking active/analysis modes, faster speeds, and other advanced features. Compare Promira Applications here.

Why Use Promira Serial Platform for SPI Analysis?

When testing high-speed SPI systems, accuracy, speed, and visibility are essential. The Promira Serial Platform delivers all three, making it the ideal solution for developers working with advanced or high-bandwidth embedded applications.

Compared to comparable analyzers like the Beagle I2C/SPI Protocol Analyzer, which supports SPI analysis up to 24 MHz, the Promira platform captures SPI traffic at speeds up to 40 MHz, nearly doubling the performance and speed needed for more complex, high-speed systems.

The Promira platform also offers High-speed USB and Gigabit Ethernet connectivity, enabling faster streaming and real-time bus monitoring locally or remotely. Whether debugging a prototype on the bench or collecting data from a remote system, this flexibility ensures seamless integration into any lab or automated setup.

Together, these features make the Promira Serial Platform the fastest and most adaptable SPI analysis tool in the Total Phase lineup, built for engineers who need both speed and scalability in one device.

Step-by-Step High-Speed SPI Protocol Analysis Example

Below, we’ll walk through an example on how the Promira Serial Platform can be used as a high-speed SPI bus analyzer. In this example, one Promira device will actively transmit SPI data to program a Flash chip on the High-Speed SPI Flash Demo Board, while a second Promira device will act as a passive analyzer, capturing and displaying the bus data in real time within the Data Center Software.

This setup showcases how the Promira Serial Platform can monitor SPI traffic up to 40 MHz, enabling engineers to observe real-time data exchanges between the SPI master and target device.

Tools and Setup

The following tools will be used in this demonstration:

• Promira Serial Platform with SPI Analysis – Level 2 Application
• Promira Serial Platform with SPI Active – Level 3 Application
• High-Speed SPI Flash Demo Board as our target system
• Data Center Software
• Promira Software API
• 2 34-pin to 10-pin cables for connection to the SPI bus
• Micro-USB or Ethernet cables for connecting the Promira devices to the PC

Promira Devices with High-Speed SPI Flash Demo Board

Connecting the Hardware

1. Connect the active Promira to the High-Speed SPI Flash Demo Board using a 34-pin to 10-pin cable. This Promira will act as the SPI master, sending data to the target Flash chip.
2. Connect the second Promira (the analyzer) to the same SPI bus using another 34-pin to 10-pin cable. This device will monitor the bus passively to capture and analyze traffic between the master and the Flash chip.
   Promiras Connected to High-Speed SPI Flash Demo Board

    

3. Use either the included micro-USB cables or Ethernet connections to connect both Promiras to the host/analysis computer.
4. Once connected, the status LEDs on both Promiras will illuminate.

Preparing the Software

1. Open the Data Center Software.
2. Navigate to Analyzer → Connect to Analyzer, then select your Promira device from the list of available devices.
3. To program the Flash chip using our API, open a Terminal window and run detect.py to confirm the active Promira device is detected. Then initialize the device and configure the settings, including the SPI bitrate at 40 MHz, before running the programming script.

Connect to Analyzer in Data Center Software

Configuring the Promira Serial Platform for SPI Capture in Data Center Software

Once your Promira Serial Platform is connected in Data Center Software, we’ll configure settings for our capture to align with the parameters of the target system.

1. In Data Center Software, go to Device Settings.
2. Under Capture Protocol, select SPI.
3. Set the Sampling Rate to 100 MHz to support SPI bus speeds up to 40 MHz.
4. Set the Bit Order to MSB First.
5. Choose Rising Edge for the Sampling Edge.
6. Set the Slave Select Polarity to Active Low.
7. Set Timeout to 100 ms.
8. Click OK to apply your settings.

Configured Device Settings in Data Center Software

Capturing and Viewing SPI Data in Data Center Software

With the analyzer configured click the Capture button in Data Center Software to begin recording SPI traffic. Once the script has run, SPI communication will appear in real time, with packets displayed in the Transaction window.

Each transaction entry includes:

• Timestamp and duration of the transfer
• Byte count
• MOSI/MISO data
• Flagged error codes (if detected)

Transaction Window in Data Center Software

Real-Time SPI Debugging and Analysis with Data Center Software

The Data Center Software has several features that help interpret and troubleshoot SPI communication as it is being captured in real time.

The Transaction window provides a real-time stream of captured packets, making it easy to identify when and where specific activity occurs on the bus. For deeper inspection, engineers can use the LiveSearch and LiveFilter functions to quickly locate particular commands, addresses, or data values within the capture log. This is especially helpful when verifying read/write sequences or isolating communication errors in longer data streams.

When a transaction is selected, the Details window displays bit-level timing and raw byte data. These insights allow you to verify that signals are aligned correctly with the clock edge and that data integrity is maintained at higher speeds.

If any errors or anomalies are detected, such as incomplete transfers, unexpected responses, or misaligned timing, Data Center Software flags them directly in the Transaction log. Engineers can then use the timestamp correlation to trace those issues back to specific events in the system, helping identify whether the root cause.

Together, these features make the Promira Serial Platform and Data Center Software a powerful combination for analyzing and debugging high-speed SPI communication in real time.

Tips for Accurate High-Speed SPI Captures

When capturing SPI signals above 20 MHz, even small configuration details can impact data accuracy. Here are a few best practices to ensure clean, reliable captures:

• Match your sampling rate to at least 2.5x the SPI clock for optimal resolution.
• Use short, high-quality cables to minimize signal reflections or loss at high frequencies.
• Confirm proper grounding between the Promira and target system to reduce electrical noise.
• Verify SPI mode settings (CPOL/CPHA) match the target system to avoid clock misalignment.
• (Optional) Leverage Ethernet connectivity for stable, high-throughput captures, especially in automated setups.

Conclusion

With support for SPI protocol analysis up to 40 MHz, the Promira Serial Platform offers engineers the speed and flexibility needed to capture and debug today’s high-performance embedded systems. Combined with the intuitive Data Center Software, it delivers a complete, real-time analysis solution for identifying communication issues and accelerating SPI system development.

To learn more about the Promira Serial Platform and its full range of SPI, I2C, and eSPI capabilities, please email us at sales@totalphase.com or request a demo.