MultiLane ML4039-BTP 100G BERT teardown, review, and experiments (plus introducing ngscopeclient)

In this video Andrew shows a board-level analysis and a block diagram discussion of the MultiLane ML4039-BTP 100G Bit Error Rate Tester (BERT), then performs several experiments to demonstrate the capabilities and limitations of the instrument. Several of the experiments are controlled with ngscopeclient, an open source tool for remote control, automation, and data analysis of complex electronic test and measurement setups.
ngscopeclient: github.com/glscopeclient/scop...
00:00 Introduction
00:33 Teardown
06:40 Block diagram analysis, theory of operation
12:34 Characterization of 300mm lossy FR4 channel at 10.3125 Gbps
16:15 Testing the same channel at 14 and 25 Gbps
19:20 Realtime oscilloscope measurement of TX waveform and output clock with ngscopeclient
24:05 Effect of TX FFE on output eye pattern
24:40 Applying external spread spectrum reference clock
27:20 Reference clock output, limitations of divided TX LO and user pattern generator
31:23 Using ngscopeclient to send arbitrary 16-bit patterns out the refclk port
32:46 Using ngscopeclient to take eye pattern and realtime BER measurements
35:25 Driving the BERT with an external source through 150mm lossy FR4 channel and optimizing DUT transmit emphasis
38:51 Concluding thoughts
I'm still figuring out audio so apologies for some of the sections that sound less good. I also realized very late in editing that I was using window rather than screen capture in OBS, so a few popup windows like file browsers didn't get captured.

[@wolpumba4099]

*Summary of the Video* *Introduction* - Review and demonstration of a Bit Error Rate Tester (BERT). - Introduction to NG Scope Client for remote control and signal processing. *Features Explored* - Equalization settings for optimizing link performance. - Real-time Bit Error Rate (BER) and eye pattern measurements. - Use of BERT as either source or sink in tests. *Experiments Conducted* - Testing at various data rates, including 14 gig and 25 gig. - Use of different test patterns like PRBS 7 and PRBS 9. - Experiment with analog emphasis on the transmit side. *Software Interface* - GUI has some rough edges and quirks. - Custom pattern settings affect all ports, not clearly indicated in UI. - Complete remote control possible via API. *NG Scope Client* - Allows for better control and visualization. - Can read out real-time BER measurements at any point in the eye. - Open-source and easy to integrate with new instruments. *Final Thoughts* - Positive about the hardware, but software needs improvement. - Looking forward to more experiments with the BERT. - Invites viewer feedback in the comments. *Positive Findings* 1. *Hardware Quality:* The reviewer is impressed with the BERT hardware. 2. *API Flexibility:* The API allows for complete remote control of the instrument. 3. *NG Scope Client:* This tool enhances the user experience by allowing remote control and signal processing. 4. *Equalization Parameters:* The BERT allows for fine-tuning of equalization settings. 5. *Real-Time Measurements:* The software provides real-time Bit Error Rate (BER) and eye pattern measurements. *Negative Findings* 1. *Software Quirks:* The reviewer finds some rough edges in the software, particularly in the GUI. 2. *User Interface:* The UI could be more intuitive, especially when dealing with custom patterns. 3. *Configuration Resets:* Changing the clock frequency causes the BERT to reset, affecting the outputs. 4. *Documentation:* Lack of clear documentation or guidance on some features. Overall, the reviewer is positive about the hardware but suggests that the software could use some improvements.

[@xDevscom_EE]

Small box that can! Thank you for sharing, can't wait to see what high speed results you'd get with it. Need to upgrade scopes to 30 GHz now? :)

[@wolpumba4099]

This is so cool. Can I play with this software without having an oscilloscope? I only have ADALM Pluto, SDRPlay RSP1 and Saleae Logic.

[@AndrewZonenberg]

We don't have any SDR support yet, but I'd like to add it. The Saleae Logic is also on the wishlist but not currently supported. But you can load data from a lot of different interchange formats (e.g. CSV, raw I/Q, VCD, binary waveform files from most scope vendors) and then use ngscopeclient for protocol decoding. So for example, you could capture activity on a SPI flash chip with the Saleae then use ngscopeclient to decode up to a list of memory addresses and read/write transactions, filter for accesses to a specific address range, etc.