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Altera_Forum
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14 years ago

DDR Reflection Phenomenon

Hi everybody, These days I have been asking some questions in relationship with some problems in a new pcb design and the communication between the Cyclone III and the DDR. Finally I think I ha...
Altera_Forum's avatar
Altera_Forum
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14 years ago

The signal doesn't look extremely bad. You should clarify trace length and exact termination scheme, signal type+direction (I guess DQ+write), used probe and probing location. Without an active or high frequency resistive probe, the waveforms won't mean much, I think. Clear quare waveforms rather than "pulses" and ns time resolution would be suggested, too.

You can refer to the respective DDR RAM termination application notes from Altera about a reasonable waveform display.