some zedboard FMC pins dead?

[devriese.wouter]

Hi

I'm currently working on a design with the zedboard (rev. D) in which I address a lot of the FMC connections.

For some reason some pins which used to work aren't working anymore (tied to ground). 
I did change my linux kernel but I don't think this could be the case/origin of problem as: I tested it by bringing the signal going to the 'dead' FMC pins also to some PMOD pins. The PMOD pins are responding, so the logic is correct, yet the same signal is not showing up on the FMC connection. (checked with scope)

Is it possible that some IO pins in a bank die and some not? As other pins in the same bank (34 and 35) are still ok and behaving normal?

 

Thanks!

[jpeyron]

Hi @devriese.wouter,

What voltage are you setting VADJ to? What other pins on bank 34 and bank 35 did you test?  Did you follow the reference manual here on page 22 in section 2.9.1 LPC FMC Connector. Is J18 set correctly? Have you tried changing the linux kernel back to verifying the FMC is still working?

thank you,

Jon

[devriese.wouter]

Hi @jpeyron

The voltage was set to 2V5, I'm addressing practically all pins of the fmc lpc connector yet a lot of them aren't responding (e.g. G15/LA16_P works, but G16/LA16_N isn't responding). It's all pins upwards actually from G15 on that aren't responding, same on H20: nothing going up (except the Vadj).

I verified with the old linux kernel, same (bad) behaviour... J18 is set correctly...

I'm wondering, could it be an issue that on my design for which I use the zedboard, I tie all the grounds together?

I'm also sure that the FPGA itself is performing it's logic since in parallel I bring out the signals to the PMODs and the PMOD signals are performing well...

Thanks

Wouter

[devriese.wouter]

Hi @jpeyron

I seemed to have solved the problem, there was an error in the linux kernel after all, I had tested with an erroneous backup.

Thanks for the assistance!

[jpeyron]

Hi @devriese.wouter,

Glad to hear that you were able to get the FMC pins working. Thank you for sharing what the problem was.

cheers,

Jon