setting for auto via to place vias despite existing cut shapes

I'm not aware of a way of turning it off. Wouldn't it almost certainly create a DRC error, unless you were lucky enough to have the vias perfectly aligned? You can always delete the existing via and add the new one, or not use "auto" mode.

Please log a service request with a good explanation of why this is useful - then we can add an option to turn off the check. The chances are that the resulting layout would not be interoperable (e.g. with P&R tools such as Encounter), so I'm assuming there's a good reason why you want to have two overlapping vias. Given that layout rules are very complex in small geometries, automation to help is generally a good idea - the point is really to try to avoid DRC errors unnecessarily - particularly if you accidentally click twice in the same area.

Regards,

Andrew.

Of course that would create drc errors.  My intention is to not leave the vias there but to get the basic number in height and reduce the number in width.  e.g.

I have a small patch of (two wide) vias in many sub cells that I need to leave alone between m5 (vertical) and m6 (horizontal).  In the particular placements of these cells I need to beef up the vertical segment for current by placing an m7 on top of the m5 and so I add the m7 and another piece of m6 vertically.  Yes, I’ll get the m5/m6 vias clobbering the sub cells but if I can just get the vertical placement I can reduce the width count so that the vias are drc correct.  The final via size that fits correctly is 257X10.  The tool would have placed 257X12. 

Because the tool won’t let me just put the vias down I have to painstakingly place first, um, let’s see, maybe 100 vias by 8, no, no, bigger.  Um, 200 vias by 10.  Ok, now the width of 10 is ok but we still need more in the height.  Well how about 300.  Nope, too big.  250?  Better but not the max.  260?  Nope, ok how about 255.  Yes!  Oh but now I’d like them centered and maybe I could fit 11 in.   You get the idea?

This used to work in 5.x and would have taken two steps not fifteen.  This was why I made the comment about Cadence getting more like Microsoft.

Thanks,

--lin

Hi Lin,

There's a new via form (currently in engineering release, so not enabled by default) in IC615, which allows creation of vias by area (amongst other things), so that could be an alternative way of doing what you want.

However, I get your point. Please log a service request and explain the above - it is a good reason for wanting to allow vias in a region which already have them.

Regards,

Andrew.