Rip up and retry not following its own rules

[kittmaster]

I'm attaching a file I'm working. If you leave everything as it stands and hit autoroute, it will make it to 112 of 113 nets. The rip up and retry times is set to 2. I turn the autorouter loose and let it go with this 1 net remaining to be laid down, I come back an hour later....its STILL trying to route 1 simple trace......

The ripup routine is supposed to kick out after TWO tries.....I think running an hour is a little more than the two time retry rule that has been set.

So I have to wonder where the problem is.

If I reduce my trace width from 20 to 18 I can get to 100% completion, but it is blatenly clear that I could hand route the trace without issue.

Any ideas to what the router is choking on?

[lacy]

O.K. I have investigated this. I will present my solution first and then comment later.

1. Goto the File Menu. Go Down to where it says Load Technology. Click it and select one of them.

2. When the dialog box comes up uncheck all boxes except Design Rules and Autorouter Options.

This should get your board routed. I am not quite sure what the technology files actually do (I will find out though), but they don't seem to be changing your original configuration (or at least I couldn't see where they did).

I hope this helps. There may be other solutions that may be better than miine and if anyone knows of a better option please inform the community.

Message Edited by lacy on 08-04-2007 11:58 AM

[kittmaster]

I saw those technology files, they are definetely a bit more "helpful" but ultimately they mean nothing since they have no points of reference or are we told what they do. Most people would not use other people undocumented technology files.

I would at least think that the default options should be sufficient to get the job done....????????

The default option in those files are also causing all kinds of drc errors because it is setting the min/max values of my traces to their options which do not fit my design criteria, thereby, making them unacceptable.

[lacy]

Yea, if your leave all the boxes checked it pops DRC errors because I think it is changing some of the options from what you have set. The thing is if you uncheck all them execept the Design Rules and Autorouter Options, I don't see where it changes anything about your current configuration (I don't fully understand it either, but it seems to work). Anyway, you are right about 2 things. The autorouter not kicking after 2 tries or whatever you have set and the default should not have much problems in such a small design. I could understand it maybe if you were designing a complete PC or something that large. Most of the time it does good, but on occasion it seems to get stuck.

Maybe on such an issue, Nestor or Max may have a better take on this.

[Tien_P]

It is really difficult to predict what Ultiroute will do, just because one setting work for one design it does not mean it will work in another.  I looked at your board and was able to get a complete route by changing any of the following settings:

1. Reduce the clearance by 0.5 mil
2. Allow Ultiroute to route off grid and this setting is under Ultiroute Options under the General tap.
3. Change the “Distance 1” from 5 to 1 under the Rip-up tab.

I see your problem with the rip up and I am not sure what is happening behind the scene but I know that Ultiroute will eventually exit, your board takes a really long time.  Typically, I will let the router go as far as it can and when you look at the bottom of the Ultiroute screen and see that the number of route complete is not increase, you should let it run for another minute or so and just manually stop it. 

[kittmaster]

Tien

The clearance reduction in unacceptable, these files are being done on a CNC router and that wouldn't allow the smallest tool to pass properly.

Why would i want the autorouter to go off grid when I specifically want my components on a grid as required by the specific locations of the components using component/trace snapping?

My question is: why do I have to manually stop the router, isn't it supposed to not paint itself into a corner and kick out with after it can't get to 100% based on number of tries?

While I understand why you did what you did, and I've already had to compromise my trace widths to get to 100%, it seems that the router is very deficient. Version 9 had a great algo.....it would get to its point now, and then suddenly a subroutine kicked in and could route almost anything.....something has drastically changed in the autorouter......unfortunately, not for the better.....:(

Message Edited by kittmaster on 08-10-2007 03:37 PM

[Tien_P]

 Hi Chris

I am not saying that you should change anything to your design, all I am trying to say is that when the router failed to complete, you may have to modify certain settings, which may/may not help.  If what I suggested is going to create a problem in the manufacture process, then you should not touch those settings.

Your question as to why the router does not exit automatically is not easy to answer since we are not able to tell what it Ultiroute is doing.  Basically, the router will exit when it runs out of things to do and in this case it sees options so it will keep trying.   In general, when you see router get to a point where it is having trouble you should give it a few more minutes and then manually stop it.   In my experience, even if you let it run for a long time, the router may give you one or two more traces but if you stop it and manually route the trace, it will be faster.   I will ask R&D to look into this issue.