How to edit a part in design without changing it in the library ?

There are situations when you want to make some changes in a part that has already been placed in the schematic. For this you edit a part in the library and save it, and then update the part in design with the latest library part. It is likely that this part has been used in many other designs, and so updating the part in library will change it in all the designs. Now, this might not be always desired.

It is possible that the symbol needed a small change just for one design and so you want it to edit it in the current design and keep it intact in all the other designs and the source library.  You can do this in OrCAD Capture by editing a part directly from the schematic page of the current design and this will not update the part in source library, hence keeping it intact in all the other designs as well.

To edit a part directly from schematic page, select a part, do right click and select ‘Edit Part’ option. Part will be open in Part Editor window. Here you can modify the symbol, or the properties associated with it.

After updating the part, close the Part Editor. You will get a Save Part Instance dialog box. Here, you can choose from following options.

• Select ‘Update Current’ to save only the current instance.
• Select ‘Update All’ to update all instances which are placed in this design.
• Select ‘Discard’ to discard the modifications.

You can see that even in the design, there is a provision to update only a single instance of the symbol if you don’t want to update all the instances of the same symbol in the design.

This updated symbol is saved as a new part instance in the design cache and gets a number (like _0 or _01) appended to it, which is different from the source library. These parts point to the design itself as the source library.

This feature in the tool ensures that the source library remains unaffected from the changes in the symbol in the design and comes handy when you wish to update only a single instance of the symbol and not all the instances in the design.

Team DesignTech

Cadence Design Systems