As the speed and complexity of high-performance circuit systems increase, the limitations of oscilloscopes in pinpointing signal integrity problems have become more apparent. However, with the advent of new event localization technologies, this challenge can be significantly mitigated.
Ultimately, this advanced event location system will greatly assist PCB design engineers in quickly and efficiently identifying signal integrity issues.
Traditional method of locating signal integrity problems
The traditional hardware trigger/deep acquisition storage method offers two key advantages in identifying signal integrity issues. First, when hardware triggers are employed to lock onto relevant events, there is no dead time. The hardware trigger system ensures continuous oscilloscope operation until the target event is captured. Once the event is identified, the hardware trigger circuit activates, completing the oscilloscope’s data acquisition and displaying the event in the center of the screen.
1. This approach is highly convenient. Additionally, utilizing deep acquisition and storage technology, users need not be aware of the specific signal integrity challenges confronting the target system. They simply configure the oscilloscope to its maximum storage mode, select trigger modes such as edge or automatic triggering, and initiate data capture. The oscilloscope will record an extended screenshot of the system’s operation, enabling subsequent analysis to identify any potential issues.
2. This technique is often referred to as the “comprehensive capture and analysis” method. It has proven highly effective within the electronic design engineer community for verifying designs. However, compared to emerging technologies in the test and measurement sector, this approach does present several limitations.
3. Introducing a novel approach to pinpointing signal integrity issues: Event recognition software. This software intelligently scans oscilloscope-captured waveforms to identify various signal anomalies or integrity events. Unlike hardware-trigger methods which may experience processing delays (“dead time”), event recognition software does not suffer from such limitations. Nonetheless, it lacks the comprehensive inspection capabilities provided by deep acquisition and storage technology.
4. Event recognition software offers distinct advantages that are increasingly appealing to oscilloscope users:
1. Simultaneous monitoring of multiple events: Unlike hardware triggers limited to specific events, event recognition software can concurrently monitor up to five events across multiple channels. This capability accelerates the process of isolating complex signal integrity issues.
2. Identification of recurring events: While hardware triggers typically capture a single occurrence of an event, event recognition software can detect and analyze multiple instances of the same event within captured waveforms.
3. Event navigation: Unlike manual waveform review, event recognition software allows intuitive playback and navigation through captured waveforms. This eliminates the laborious task of manually inspecting vast amounts of waveform data.
4. Detection of diverse events: Unlike hardware triggers limited to a few predefined types, event recognition software can isolate a wide range of events measurable by waveform analysis, including complex phenomena like non-monotonic edges.
5. Speed of event identification: Event recognition software operates digitally, leveraging high sampling rates of modern oscilloscopes for rapid event detection. This surpasses the speed limitations of analog-based hardware trigger circuits.
5. The combination of PCB design software and event recognition systems enhances efficiency by generating trigger classifiers or by limiting the waveforms analyzed by software. Event recognition software complements traditional hardware triggering and deep acquisition methods in identifying signal integrity issues.
Overall, as technology advances and signal frequencies increase, event recognition software stands out as a flexible and effective tool for addressing signal integrity challenges in electronic design.
