topic Re: Autorouter: Can I set up the layer to be routed? in EAGLE Forum

Autorouter: Can I set up the layer to be routed?

aa4649 — Wed, 10 May 2017 10:37:09 GMT

Autorouter: Can I set up the layer to be routed?

I am using EAGLE 8.1.1.

I enabled LAYERS 1, 2, 8, 9, 15 and 16.
8, 9 = power layer, 1, 2, 15, 16 = signal layer

I thought about routing other than the power supply signal to 1, 2, 15, 16.
Connect the power supply using VIA to 8 and 9, and connect with polygon.
Several signals of BGA use all the layers 1, 2, 8, 9, 15, 16.

Method 1:
Auto ! * 3.3 * * gnd * (LAYERS (8) (9))
This setting can not be done!

Method 2:
Preferred Directions 8, 9 = Set to N / A and execute autorouter.
Because it overwrites the BGA signal of the 8 and 9 layers, an error occurs.

How can I do it well?

Re: Autorouter: Can I set up the layer to be routed?

edwin.robledo — Thu, 11 May 2017 00:12:33 GMT

Hi aa4649,

Greatly appreciate your participation on the forum, I hope to provide you some information that will assist you.

If possible, please go to DRC/Layers and let us know what is your setup. The autorouter does a great job but remember it needs to be influenced. In this instance, I would recommend changing your bump up your layer cost for all sections of the route. Keep the preferred layers 0, then set the other layers to other values according to the order you want it to follow.

Also remember you can use the Autorouter multiple times. Have it do some signal first, then change your DRC and Autorouter setting for the remainder of the board. The Autorouter will not optimize routed traces.

You mention you have multiple BGA's, why not use the BGA Fanout router to take care of these first, then do the rest of the board using the autorouter.

I hope this helps.

Best Regards,

Re: Autorouter: Can I set up the layer to be routed?

aa4649 — Thu, 11 May 2017 03:14:06 GMT

Thank you.
I set Layer cost to 99 and it worked fine.
Is it OK with 99? How is it with a little smaller number?

Autorouter Main setup has "Auto" setting in Prreferred Directions.
There is no "Auto" in Prreferred Directions of Routing Variants Dialog.
What is different? Is * and Auto the same behavior?

Autorouter Main setup / Routing Variants Dialog has Load, Save as respectively.
Save the configuration file with Routing Variants Dialog.
Next, you can not read the setting file with Load of Autorouter Main setup.
What is the difference between the configuration files of both?

Re: Autorouter: Can I set up the layer to be routed?

aa4649 — Thu, 11 May 2017 03:48:44 GMT

Re: Autorouter: Can I set up the layer to be routed?

jorge_garcia — Fri, 12 May 2017 18:13:45 GMT

Hi @aa4649,

I hope you're having a great day. Thank you for participating on our forums!

On a multi-layer board with blind and buried vias this is currently not possible. The only way to do it is to set the specific layers in the Autorouter dialog to N/A. The problem with doing this is that EAGLE completely ignores whatever is on those layers as if it didn't exist, so it's very possible to have via collisions because the autorouter won't see any vias on the disabled layers.

Since I don't know how your vias are setup, I can't be too specific however there is a way to force via drops to the power planes. You have to setup the autorouter to only do short segments and then drop vias. I've attached some configurations you could use for this. You'll have to modify the layers to match your board, but the general setup should work.

You'll be routing in passes. First the connections to all the planes.

1. Type AUTO GND 3.3<enter key>

2. The autorouter will only want to route those two signals. In the dialog the pops up select load and pick on of the two via files I sent.

3. Adjust your layer settings in the general tab as you see fit.

4. Run the autorouter.

If everything worked correctly for the most part you should see that there are vias connecting to ground planes. If you are happy you can now run the Autorouter again but this time you want to load the default setup. Now let EAGLE run on the rest of your board.

At the end of Chp7 of the EAGLE manual you'll find information about how those via drop configurations were made.

Please accept as solution if my post fully resolves or you issue, or reply with additional details if the problem persists.

Best Regards,

Re: Autorouter: Can I set up the layer to be routed?

aa4649 — Sat, 13 May 2017 00:33:55 GMT

Thank you, all.
Maybe I will not use blind and buried vias. For now it's okay.

I modified the unrouted.ulp of the library. Make a forced Vias for all power supply and ground.
And this way; "There is a way to force via drops to the power planes.It setup the autorouter to only do short segments and then drop vias."

Suggests:　Make "Power", "Ground", "other signals" file set of * .. ctl. Make it switchable by AutoRouter. Like CAM and v8.2.0 Layer display set.

It shows a successful way (but cumbersome!).

EAGLE PCB CAD, a method to create a 6-layer board with a power layer and a ground layer.

Read in the six-layer configuration file DRC.
6_015035.dru

In the layer setting, make GND (8), Power (9).

List the signal names of the power supply and the ground, type show and auto ! ("!" Can specify the "other" signal with AutoRouter)
Show *3.3* *gnd*
Auto ! *3.3* *gnd*

Use Not Power, gnd 0.25.ctl:
Set "Routing Variants Dialog" to ">>" and set the cost 99 to 8 and 9 on each tab (not automatically routed to the layer where 99 is set).
Auto! *3.3* *gnd*
Signals other than "*3.3* *gnd*" are automatically routed to 1, 2, 15, 16.

Use Power0.25.ctl:

Set only 9 of each tab to 0 and set the remaining 1, 2, 8, 15, 16 to 99.
Auto *3.3*
"*3.3*" is automatically wired to only 9.

Set only 8 for each tab to 0 and set the remaining 1, 2, 9, 15, 16 to 99.
Auto * gnd *
"* Gnd *" is automatically routed to 8.

Finally, create a solid ground with polygons.
Isolate 0.254, to Rank 5.

A clean solid GND was created on layer 8