02-10-2019 06:20 PM
I am trying to use the GTH transceiver for 10Gb ethernet on the Avnet Ultrascale Kintex development board. I modified the example design, program it thru a JTAG cable and was able to maintain an IDLE link to a 10Gb ethernet NIC on my PC. However, something strange happened to the design.
After I leave the design on the board for 1-2 days, the design will stop working. And using the VIO within the core I can see that the core was somehow reset (which I dunno why) and the reset is not complete. Moreover, I can see that the "gtpowergood" signal of the core is not high and thus the reset is not completed. I tried to reprogram the FPGA with the same image but the GTH will fail and stuck at the same stage even if I reprogram the fpga.
Finally if I power cycle the FPGA and load the same image, everything will turn back normal.. for a day or two.
Has anyone encountered the same problem before?
02-14-2019 04:05 PM
Have you probed the power supplies (MGTAVCC, MGTAVTT, MGTAVCCAUX) on the board when the issue happens?
02-14-2019 04:14 PM
I would install an ILA to monitor the reset and reset state machine to try to track down what is triggering the reset. Could the FPGA be getting too hot?
02-15-2019 05:08 AM
I am using the avnet kintex development with ku040
It turns out that the 1.8V mgtvaux voltage to the FPGA will sometimes turned off (I can see the LED of that power rail is off). And that's why the GTH stop working.
However, I cannot figure out why that power stop working. I've pull-down all the unused PINs. So I suppose the 2 I2C pins connected to the programming interface to the PMBus power supply will be off too. Don't really know what happened.
Does anyone has any experience using GTH on this particular board?
02-18-2019 02:05 AM
there could be many reasons why a power supply drops. Somethimes it is just the voltage regulator enabling the overcurrent protection. You might try to stress the device and force an high current (there are examples of hammer test) or high temperature.
Probably the Avnet board comes with a schematic: from the power supply datasheet you could try to discover if the power supply has margin respect to your design.