share your opinions on autorouters?

[Jayson]

keepout spectra autorouter

can someone share their experience with autorouters, like Specctra or others.

Is an autorouter like specctra reliable for routing a whole board or does it require interactive editting, and how much interactivity is required?

- Jayson

 

[wwwxuli]

I use PowerPCB to do placement and divided the ground and power plane, then I set the design rules for clearance, at last I convert it to specctra to route, all of wires are routed in specctra except the clock signals, becaue the arc wire in PowerPCB will be changed to acute angle.

I wonder whether it is necessary to set design rules by language in specctra.

 

[Jayson]

do you autoroute in Speccta or do you use interactive routing?

- Jayson

 

[AG]

If you want good result route manually your pcb. :wink:

 

[eltonjohn]

I Guys

I have routed boards for many years now . But just small boards .No big deal up to 6 layers .. I well know from experience that sometimes is better to route it by hand .. But it has always been a curiosity for me HOW those HI DENSITY PC MOTHERBOARDS are ROUTED? .. Doing it by hand will seem like to TAKE YEARS !

Any body knows??

 

[eternal_nan]

I reccommend all of the sensitive/high speed signals on your board by hand and letting the autorouter do the rest. Also, I noticed cheap autorouters (like the ones built into protel and orcad) tend to work better on boards with <4 layers (like most hobby projects) than expensive ones (like specctra) do.

eternal_nan

 

[binu G]

i use power pcb for the placement and design rules
routing i preffer spectra, but not auto routing manual routing in spectra is very effective than routing the board in the power pcb, and it can be fast too .
binu

 

[Frosty]

Autorouters will only do what you tell them. These beasts are 100% rules driven. The time is in the rules definition as regardless of what it says on the box, some rules regarding grids or 'channels' will conflict with other rules such as grid settings vs trace width settings, clearance, net length matching, diff pairs, clock from toos & termination and so on.

Sometimes the time to set up the rules is more than the time to route manually especially if you have a lot of mixed analogue/digital rules to follow and use split planes.

If you use software for capture that will translate all PCB rules defined at SCH level to be followed by router then you will save time. Protel does not do this, or at least does not allow for proper rules definition in SCH yet with enough parameters to work on a dense design.

For a mid range router, well integrated into the tool suite Pads is pretty hard to beat with Blaze.

Specctra is really cool but I have not seen it work well with other tools, based on quality of rules translation and interactivity level, outside of Cadence suites. But no suprise there of course

The Specctra interface is where most non-cadence tools fall down, but I beleive PCAD works very well with it as they used Specctra for many years anyway.

All down to time, and in some cases available CPU time & lots of RAM!

Howver most routers can help in routing some of the sh#t work like fanout, memory arrays or reptative routing and so on. Even the cheap built in ones do this OK most of the time.

As regard PC motherboards routing, the last project I was involved with long time ago was a team effort and they used Specctra, based on a Pentium Pro CPU, the time allocated for defining and optimising the rules, of which most can be obtained from most vendors or associated standrads anyway, was 6 months!

Cheaper to buy a mobo these days

:R

 

[asit]

What you guys suggest for single layer small PCBs with jumpers?

 

[borisov57]

I am in process of routing double sided 160mm x 100 mm board with usb contoroler, dsp, ram, two din96 connectors and some other chips and connectors. OrCad smartroute almost finished it with 3 conflicts. The "best" router specctra left 18 unconnects behind and even "better" autoactive leaves 35. Blaze manage to route to 5 opens after running half night long on 450Mhz computer.

 

[jhenxl]

Despite what margeting people says, i have found autorouters behaving poorly. Especially when you are routing mixed-signal pcb. There has been couple occasion when autorouter has routed clock signal over analog groundplate. Though the problem might be in a user. But anyway i think you get better pcb when you route them by hand.

 

[phonedrop]

can someone share their experience with autorouters, like Specctra or others.

Is an autorouter like specctra reliable for routing a whole board or does it require interactive editting, and how much interactivity is required?

- Jayson

It has ben a while since I used the specctra router, V 10.0 was the last realease. I had a pcb that had .5 meg worth of high speed roule and there was no way I could finish on time with out the auto router. Sure there wee routes that I could have done better by hand, but with the auto-router we were able to tell what constraints were going to break and it forced the engineering staff to prioritize the rules.

pd

 

[Vicent Yang]

For single side PCB the best thing is to do the routing manually because for single side PCB you will need a lot of time to set the rules for the router.

 

[neerajs]

We have found Specctra to be a good autorouter ofcourse one need to set the rules correctly..

 

[Mart]

I use it only (powerpcb spectra) for non critical digital lines with keep out planes.

But still, if you want a good result route manually your pcb.

 

[Frosty]

What you guys suggest for single layer small PCBs with jumpers?

You can have an auto jumper insertion feature within Pads PowerPCB.

Jumpers can be inserted 'on the fly' while routing the board.

 

[elektryk]

HOW those HI DENSITY PC MOTHERBOARDS are ROUTED? .. Doing it by hand will seem like to TAKE YEARS !

Not quite, for example, industrial computer system-on-chip+ram+flash+CF+ some minor stuff, about to 200 'wires', four layers (signal/mixed/ground_plane/signal) is calculated to be made by SIGNLE person about 50h.
Personally I use EDA soft for small project, (uP+minor stuff), and I am using Protel and Eagle. For 1 or 2 layers pcb made by eagle looks much better, Protel has tendency to route like 'dumb'

 

[rauol]

Has anybody tried ULTIRoute :roll:

 

[henrik2000]

Well as far as auto router is concerned I love Specctra. specifically when different area of the board should be routed with different rules. When routing 12 to 15 BGA's with 208 to 450 pins or more I would love to see someone do that by hand! (I think someone mentionned that he (she) prefered hand routing??
I do agree with the fact that passing constraints from schematic is not always the best way to do it. Rather write a 'do' file or define with edit route various constraints..
For high speed signals, either with controlled impedance and or capacitance, I admit that Specctra does an exellent job.

Placement by another and routing by specctra, gives me best results.. But that is just my opinion.

Cheers.

 

[year]

I use only autorouter for making test board.
It is not bad. But production is differnt case.
Because, there are lots of limit to use autorouting.
But partialy I use...
So, I do not want you go and back for autorouting.
It is only your decision.