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Recently, a similar module had been implemented successfully on the same board. Is there other reasons for the above phenomenon except for some hardware problem ?
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A hardware problem or error on your part connecting the pins is by far the easiest problem. A quick sanity check on that would be to simply assign the 2nd PHY to the 1st MAC and vice versa (i.e. does the problem follow the PHY). If the 2nd PHY starts working and the 1st PHY stops working, you know that you have incorrectly configured/connected the 2nd MAC somehow.
Beyond hardware / pin connection problems, you should review your MAC signal connections, specifically the clocks/resets/streaming interface. It may be worthwhile to skim the Quartus output and look for warnings that are present for one MAC but not the other.
But in your shoes, I would revisit the known-working system and review differences between it and my broken system.
Good luck.
Honored Contributor
