Notice that this measurement was taken with one of the Chip Select lines hooked up. You can see that its data valid window is smaller than that of the other command bus signals. This is due largely to the use of soldered wires to connect the Chip Select signal. Eye Finder provides a convenient way to make sure that the wires you use to connect to the Chip Select test points are not too long to get a valid indication of which DIMM is selected (or to make sure that signal integrity for the Chip Select signal is not overly compromised).
Step 2 – Write Burst Data Valid Position
For this step DDR bus activity must include a high rate of write bursts. Memory tests or video clips are usually a good source of such activity. To measure the write burst data valid position, start the stimulus on the DDR bus. In most cases the stimulus will contain a mix of read and write cycles. If this is the case, you must set the switches on the DDR probe to select only write bursts to be clocked into the analyzer
Open the Eye Finder control panel on the logic analyzer capturing data. Run Eye Finder and note the results. Depending on the density of bursts in the stimulus you may find that Eye Finder could take quite a while to run. In general, the denser the bursts the less time Eye Finder needs to complete its work. If the density is too low then Eye Finder may take as much as 30 minutes or more to run, or may terminate within a few seconds and report that not enough clocks occurred within a 5 second interval to make a good measurement. If this happens you can open the “Eye
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