TRW and the Wrong Way - Changing a Property on All Instances of a Cell

Properties usually apply to primitives (MOSFET, R, C, etc).

Your schematic has a few FETs making up a current mirror (say). You want to increase the L of all of those making up the mirror. What's the easiest (right) way and what's the common (wrong) way?

Wrong way

Assume that the type of FETs (cell from the PDK) making up the diode and output sources are used ONLY in the mirror. 

You could select one, press q to bring up the property form and then change to "All" and then make the change.


Cost - you'll have to change the "All" back to "only current" - else it's going to work against you when you don't want it to, later..

Another wrong way - select all (in this case, unnecessary, but necessary if there are other components besides the mirror using that primitive) - and use the properties form with the "Apply to" changed to "All selected"

The Right Way

Install my bindkeys so that you have ALT+SHIFT+Q available to apply-to-all-selected without having to change any settings in the form

  1. Select one of the instances in the mirror. 
  2. Press CTRL+ALT+H to select all of the same master
  3. Now, press ALT+SHIFT+Q to bring up the prop form set to "All selected"
  4. Make your change and press ENTER.

The bonus - if you want to edit one instance later, you can press 'q' and see that the form is still set to "only current"



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