Creating transistor nodes with multicut rules in Electric tech. editor

[Andrew West]

Hi,

I've been working on creating an Electric technology library so it can be
used for full-custom designs for our chosen foundry. Largely I have had no
problems and have successfully extracted and DRC-checked Electric's GDS-II
output with third-party tools.

The problem I now have is that I can't make nMOS and pMOS transistor
primitives where a varying number of Active-Metal1 contacts are inserted
as the transistor is made wider. As far as I can determine, the Electric
technology compiler does not seem to determine multicut rules for
transistor primitives. The 'mocmos' technology source file provides
additional C routines to allow it to do this for the
'*-Scalable-Transistor' primitives.

Can Electric's technology editor derive multicut rules for transistors?

I have tried numerous examples, for instance:
  http://www.cl.cam.ac.uk/users/afw27/transient/scalable.gif
In every case I have tried converting the library into a technology
Electric has either complained about unassociated contacts, differing
number of contacts in the examples or failed to infer the rule.

What I would ideally like to do is to instantiate an nMOS primitive and
then change the width from, say, 100 to 1000 units, and have Electric
automatically add more contacts. Is this possible just using the
technology editor to create the technology library?

If not, does this mean I have to integrate the mocmos
'Scalable-Transistor' code into the dumped C code of the technology
library I have built, or can anyone offer an easier way of doing this?


Many thanks,

Andrew West