XCore 2 is not enabled error in 4 processor pipeline

[JohnWilson]

Seperate clocks for each core, and seperate supplies.

Just curious: are you just observing what's in the photo (I see a separate xtal on each XS1), or are you saying it's an important thing to do? I just did rev 1 of a proto PCB with two XS1-L-128s which share one 20 MHz xtal osc -- am I going to regret it?

Anyway, this is a beautiful board!

John Wilson
D Bit

[bearcat]

Just curious: are you just observing what's in the photo (I see a separate xtal on each XS1), or are you saying it's an important thing to do? I just did rev 1 of a proto PCB with two XS1-L-128s which share one 20 MHz xtal osc -- am I going to regret it?

I don't say it is right or wrong. I did not understand the choice for seperate clocks. Seperate power supplies might be any easier argument, but still seems an expensive choice. I was hoping the designer would chime in on his choices so I might learn something myself.

[narutoxela]

Seperate clocks for each core, and seperate supplies.

Just curious: are you just observing what's in the photo (I see a separate xtal on each XS1), or are you saying it's an important thing to do? I just did rev 1 of a proto PCB with two XS1-L-128s which share one 20 MHz xtal osc -- am I going to regret it?

Anyway, this is a beautiful board!

John Wilson
D Bit

I think that putting multiple XMOS chips on a single osc could be a bad idea. It depends on how much current each chip is pulling on the CLK input because on average (based on a simple research), the output of an osc can give only 5mA. So, I was thinking that putting an osc on each XMOS chip reduces the risk of overloading the osc itself.

[rp181]

Hey, sorry I didn't chime in before. While having 4 supplies and clocks does offer redundancy, it wasn't the primary reason. It simply made routing the PCB easier. The additional cost was very minor to the project as a whole. Time was the limiting factor.

BTW, the supplies are tied together. Also, the system it is a part of draws a good amount of power, so multiple supplies is advantageous.

[rp181]

Another note:
If you use multiple 1V supplies, don't tie them together. They won't current share properly.

With a single clock, be careful of routing the noisy line.