Debug Serial Bus Errors with Oscilloscope Hardware Serial Triggers
Application Notes
As a high-speed serial interface designer, your job is getting even more complicated as data rates continue to increase:
– The physical layer design complexity is increasing exponentially.
– System noise, crosstalk from adjacent lanes, or electromagnetic fields can easily distort signal integrity.
– Channel skin effect and lossy signal path are degrading the signal integrity further, causing an increased bit error rate (BER) at the end of the channel. As a result, the receiver is likely to end up with a signal that has a closed “eye”.
– High bit errors in the data transmission, due to a combination of physical layer issues or protocolrelated errors, can cause interoperability issues.
Any of these phenomena will reduce the reliability and robustness of the design system used.
Designers regularly use the analysis capabilities of oscilloscopes to validate and debug highspeed serial bus designs. They use tools such as eye diagram plots and jitter decomposition to characterize the bus performance. However, even though these tools can help you quantify the overall performance of the physical layer, they tend to have a hard time identifying and debugging the root cause of system problems. It is difficult to determine whether the problem is related to the physical or protocol layer, and even harder to pinpoint the root cause when the error happens infrequently. Conventional oscilloscopes are limited by the long dead times of their acquisitions, which means that infrequent errors or events are missed. You will see that Keysight’s V-Series oscilloscopes with the hardware serial triggering option tackles all of these challenges so you can quickly identify and debug the high-speed serial bus errors.