LvsIgnore Properties

 Try "lvsIgnore".  Lower case for the first char and use "TRUE" as value, all upper case.

Regards,

Marc

It works. I was using effectively lvsIgnore but not "true" in upper case. Thanks for the tip.

 Hi,

I am using IC6.1.3.500.17. Setting "lvsIgnore=TRUE" simply removes the element from my generated netlist, leaving dangling wires behind. I am not sure if this is the intended behavior or the result of some hack in the design kit I am using. Nonetheless, I would like to know if there is a switch I can set on an element so that it gets shorted out in the netlist.

Something like "lvsShort" would be handy. Is there such a feature available?

Thanks,

Vivek 

There is a property lxRemoveDevice (which started off life for Virtuoso Layout XL) which can remove devices and short in the process.

This can also be supported in other netlisters (from IC61X), and is covered in Cadence Online Support Solution 11490734.

Alternatively, if you're using Assura (or indeed Diva) these have commands (removeDevice, filterDevice or something like that - can't remember without looking it up) which allow you to define LVS rules to short a named device.

Regards,

Andrew.

Thanks for the post. The solution does look very promising but there's a small albeit logical caveat. It works only if there are just 2 terminals. This is good enough for pretty much all cases, but I happened to have an element which has a third terminal whichis not DC connected to the other 2 (like a substrate connection) but that's enough to prevent it from being shorted out in the CDL.  I see an error message in the si.log complaining about this.

Looks like I need another solution. At presen though, I am simply wrapping the 3-terminal element in another instance with only 2 terminals and getting around the problem, although this is less elegant especially since I cannot pass the underlying CDF parameters so well especially if they were to change.

Vivek

Actually, there is a slightly better solution for the case where one would like to short out 2 terminals of an n-pin device in the CDL.  Simply add a 0 F capacitor between the 2 terminals that need to be shorted out, and set the lxDeviceRemove flag on this cap. Of course, it is important to ensure that no other terminals are shorted out (internally in the n-pin device). If possible, the lvsIgnore flag can be set on the n-pin device itself eliminating it and precluding the possibility of shorting out anything else.

Vivek 

Should i understand this trick will work only in OA environment and not in 5.41?

 The properties for ignore and short will work in 5.1 as well.

Andrew,

 I tried this trick, it does not work for shorted nets for 4-terminal devices, but does work for opened nets.

 Thanks

Kristin

Kristin,

I am working with the OA environment (see previous posts), and this trick works quite well for me. I used it to short out 2 terminals of a multi-term device.

Vivek