Executive Summary
“Spare cell insertion is a well known technique to reduce the cost of functional fixes, limiting the changes to a few metal masks. Common practice is to tie to ground the spare cells’ input pins, reconnecting them later in the flow, as required by any functional ECOs.
Project Highlights
![](https://www.einfochips.com/wp-content/uploads/2014/05/027-spare-cell-leakage-minimization-in-physical-design-part-1.jpg)
For illustration let’s take a NOR gate spare master which has 2 inputs A1 and A2. This gate will have four different states of A1 and A2 and hence four different state-dependent leakage power values. This gate would be summarized as shown in Table 1.”