Bug in PCB routing and checking -- critical

[henrik.stenlund2P6MU]

Hi

we have successfully designed a few complicated and some simpler boards while using EAGLE 6.60 Professional. Now we had a fairly simple cpu board and noted that it is not working. It took a while to recognize that two wires are not routed by the Autorouter. Also the statistics does not indicate anything missing.

The netlist is OK and so is the schematics. Two chip pins are totally ignored. The same kind of logic chip is used onboard already so it is not a footprint error. If one wishes to manually route it, it is not possible since the router sees the board as completed. If one tries to use the Autorouter to complete the two missing wires, there is nothing to do. One can manually force routing by using named wires and thus complete the wiring. 

I think this error is alarming. I ask the manufacturer to quickly upgrade with the bug removed, the older version V6.60 included. We have no plans of going to higher versions at this time. I can supply the design files for troubleshooting.

[henrik.stenlund2P6MU]

Hi

Now that everything has been checked and rechecked a few times  I can see that we were wrong. Sorry for this.

There is a minor gap in the schematics wiring disguising the fact that there is actually no connection. Also the netlist was reflecting it properly.

Sorry guys!

[henrik.stenlund2P6MU]

Hi

the original mistake was ours by leaving a small gap in the wiring.

However, EAGLE does not warn of this in the warning list. These two chip pins are not in the warning list, all others are. We would absolutely have detected this fault if it were. This IS a bug in EAGLE.

Henrik

[jorge_garcia2]

Hello Henrik,

I hope you're having a good day. If there were still airwires remaining, you could have caught them by using the RATSNEST command, it lets you know how many airwires are left.

The DRC doesn't report unrouted airwires because you have the net defined. This has been a hotly debated topic historically about whether the DRC should report unrouted airwires or not.

I'll bring it up to the developers again to see if it can be discussed and some sort of resolution can be arrived at. In the meantime before sending a board off for manufacture run ratsnest and look at the bottom left of your screen if you see nothing to do then you can be confident that all of the copper has been routed.

If I have misunderstood the problem please let me know, at that point I may ask to review the files.

Let me know if there's anything else I can do for you.

Best Regards,
Jorge Garcia

[henrik.stenlund2P6MU]

Hi Jorge

and thanks for your assistance.

We always use the ratsnest etc. to finalize the design.

The problem this time was not the pcb itself but the schematics. We had accidentally left two small gaps between the wires to pins. It was easy to ignore it. And this will lead to the final problem.

However, the half of the problem is from the EAGLE's schematic editors checking utility. It does not recognize these empty pins although it will report other unused pins. So, in my mind there is some bug in this facility. Otherwise we could have observed the error already in the schematics phase as we always go through the warnings.

Best regards, Henrik Stenlund

[jorge_garcia2]

Hello Henrik,

I hope you're having a good day. Ah Ok... Normally the ERC would catch this by reporting a close but unconnected warning. In the new Autodesk EAGLE we've added a new feature where nets will snap to the pins that way you can never run into this situation of having a gap between nets and pins.

Thank you for the clarification.

Let me know if there's anything else I can do for you.

Best Regards,
Jorge Garcia