I am interested to know if these's a way to create a stacked VIA, say a stack of VIA4 & VIA5 in a 6 metal process.
I am interested to know how do I add this Stack VIA in the technology file? Can I add it to the tech file throught an API like the CreateStdVia & the CreateCustomVia? Or should I specify it in a constarain group entry(desired one),
I need Via4 & VIA5 placed one over the other.
Thanks in Advance.
Which version are you using? The answer is different between IC5141 and IC613.
I am using 6.1.3
In that case, you should use Create->Via and then select "Stack" and you can enter the start and stop layers. It will create a stack of vias. Yes, it's multiple via objects, each of which is between a pair of layers, but this has the advantage of being simpler, and also better understood by multiple tools.
If you use create wire, and change through multiple layers (e.g. hit the space bar to change layer), it will place a stack of vias for you.
Also, in the "Options" toolbar there is an icon to control whether Via Stack selection is on or not (this also appears on the Options->Selection form). What this does is ensure that if you click on a stack of vias, it selects the entire stack, rather than just the individial vias.
So there really is no need (and indeed it's not recommended) to create specific stacked vias in the tech file.
This is the exact way I am following now.
But I am trying to get the following mechanism work :
( "Dummy_via_group" nil interconnect( ( validLayers (NW OD PO1 M1 M2 M3 M4 M6 ..... ) ) ( validVias ( M1__PO M2_M1 M3_M2 M4_M3 M5_M4 M6_M5 )) ) ;interconnect ) ;If I select the following via group and create a wire, when I move from M4 to up , it mus place a stacked Via containing M5_M4_VIA & M6_M5_VIA
What changes do I do in the technology file if needed to achieve this.
You don't have M5 in the valid layers. If you have M5 in the valid layers, you can hop from M4 to M6 and it should put both vias in, as a stack.