On Do, 2017-08-31 at 17:30 +0200, H. Nikolaus Schaller wrote:
Hi,
Now I have done that and capacitors have not changed since the first CPU board prototype.
Ah, okay.
As it works for Tony if he increases the voltage and Juliano showed that we might have too much noise, then a LITTLE improvement might already be enough. So those >3 per DDR3 could help!
Yes, according to this completely unproven theory. I just want to say that I would prefer new facts before drawing conclusions from hypotheses :) I understand that you prefer to really do something than still be digging in the fog/mist.
Unfortunately it is hardware and not changing some line in source code and recompiling :(
I know, that's why I asked in my first mail whether someone has an idea what we could still check. What doesn't make sense is when no one tries anything in software anymore because there are no new ideas or everything has been tried already.
That would be a total standstill for hard- and software and that's worst case scenario.
Especially since changes cost money. >3 per DDR3 chip means:
- scrapping the 500 boards and
- trying to squeeze in more capacitors
- have PCBs built and populated
If it helps: fine. If not: wasted money and time.
Yep, I know. Scrapping the 500 boards would only make sense if it turns out to be the issue though. And if it IS the issue, then scrapping them would be the right thing to do.
But if no one knows another solution to try in software and nothing happens for about 8 weeks, we would have the time to build new PCBs.
So sure, finding a software solution is the highest priority, but if there are no ideas left we can't just sit and do nothign.
The change-compile-boot-analyse cycle for software is significantly faster...
I am well aware of that. But if you tinker around for 8 weeks and find out nothing helps, you still lost 8 weeks.
If you try to improve the PCBs and order a prototype sample, you can still tinker around. If you find the solution: Great! If you don't, at least you don't have to wait another 6 weeks for an improved PCB.
So yes, as long as there are more ideas and things to try, I don't want to try to fix the hardware. But once all ideas have been tried out, I don't want to waste any time either.
So I'd prefer to get more facts about different parameter sets that work/don't work etc. first.
Well, according to the distributor, they should work with standard Jedec timings without any issues. Same as the 2GB RAM.
If they don't, then they suggest to fix the hardware.
I'm fine if we use non-standard timings, of course (as long as it works), but according to the distributor, there shouldn't be much to setup in software, which is my biggest concern.