W5500 receiver intermittent problem
Our W5500 board works perfectly fine with sending packets, yet the receiving function does not work – most of the time. However, the receiving function DOES work perfectly sometimes, and there is no change of the code whatsoever, – the only thing that will change the state from not working at all to working perfectly, is by power cycling, ie. by turning the power on/off many times.
We have checked many aspect of the design. We do notice that if the receiver works, the ACT_LED will blink with each arriving packet. If the ACT_LED does not blink with arriving packets, then the receiving function will not work. Based on this observation, our guess is that the PHY portion of the receiver might have some problem, yet in W5500, the user has very limited access to the PHY layer, basically the PHYCFGR, which we have checked tooooo many times, tried all possible combinations, yet the problem remains the same.
At this point, we are really puzzled at this problem. Could you give some suggestions?