01-20-2016 12:55 PM
Hello. I seem to be having an issue with my Arty board. I've been playing with the board for a while now without any game stopping problems on the software side. Issues started when the designs I was implementing didn't seem to be programming at all. I built an incredibly simple barebones design that consisted of just an input and output buffer for the 100M onboard oscillator, which I know I had gotten correct since it was a part of my previous larger design, but I'm not seeing any signal on the output of the pin I've assigned it to here.
I went back to the schematic and noticed that there is a PWRGD LD11 that is no longer on. I'm not sure at what point it stopped turning on, but I know originally this LED was on before. For reference, LD8 is still shining when I apply power. From what I've gleaned from the schematic, the LD11 turns on when IC11 determines the supplies are working. I've probed all of the different supplies coming from IC11 and they seem to all be working on their nominal levels. I'm also still able to program the device via Vivado without any hiccups, but once I try to apply my external signals (including something simple like the 100M onboard) there's no sign of life on any of the outputs. I would assume if the device really wasn't getting any power, then Vivado wouldn't find the device or let me program. So the LD11 issue might be unrelated.
Any thoughts on how I could troubleshoot this issue?
01-27-2016 10:15 AM
As stated in the reference manual, "A power-good LED (LD11), driven by the “power good” (PWRGD) output of the ADP5052 regulator, indicates that the board is receiving power and that the onboard supplies are functioning as expected."
It sounds like you may have a defective board. You can go back to wherever you purchased the Arty and request an RMA. If you want to try one more thing before doing that, use a known good existing design rather than building your own. There is one available here -- www.em.avnet.com/arty --> Support Files & Downloads.
01-27-2016 02:10 PM
Ok, well I downloaded the GPIO Demo design and I was able to program my board succesfully, buttons and switches controlling the LEDs and all.
I would have to assume my LD11 failure has nothing to do with my project not giving the right results, yes?
01-27-2016 02:15 PM
The PWRGD signal does nothing else on the board then light the LD11. It is not used for a POR. Therefore, if the issue is isolated to the PWRGD to LD11 path, it would not effect the function elsewhere on the board. However, it is still a malfunction. If you are within the warranty window and want a fully functional board, then go the RMA route.