The "at Pin" waveform is the waveform observed on the pins of the device, and the "at Die" waveform is the waveform observed on the die of the device (specifically, the IO buffer).
The actual waveform recognized by the device is the "at Die" waveform.
If the at-die waveform is well formed and meets the IO characteristics of the device and IO protocol standards, it can be judged that the actual device recognizes the waveform correctly.
However, even if the at-die waveform is clean in the board simulation, it is not possible to measure the waveform at the at-die point on the actual device.
The points that can be measured on the actual device are near the pins, so it is necessary to compare the at Pin waveform with the at Pin waveform of the board simulation.
In other words,
the waveform measured in the vicinity of the device pin and the at Pin waveform in the board simulation are similar
=> the at Die waveform in the board simulation can be judged to be the waveform on the die (IO buffer) of the actual device
.
Therefore, even if steps or reflections are seen in the at Pin waveform, if the at Die waveform is clean, it can be judged that there is no problem.
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Category: Mentor
Tool: HyperLynx®
Device: -