We have come a long way from the days of limited and manageable characterization databases with fewer views and smaller library sizes. The technologies we are headed towards pushing characterization to its limits with special modeling for variation, aging and reliability all on a single process, voltage and temperature (PVT).… Read More
There are some metaphorical similarities between reaching timing signoff and driving a car to your destination. Most of us get in the car, turn the key and push the gas pedal to make it go. While we might have a cursory understanding of what makes it go, there are actually a lot of “moving part” under the hood in each instance. For most… Read More
The old adage that goes the one constant thing you can always count on is change, could easily be reworded for semiconductor design to say the one constant thing you can count on is variation. This is doubly true. Not only is variation, in all its forms, a constant factor in design, additionally the methods of analyzing and dealing … Read More
It used to be that at the mention of libraries, people would think of foundry PDK deliverables. However, now a host of factors such as automotive thermal requirements, nanometer FinFET processes, near threshold voltages, higher clock rates, high volumes, etc., have dramatically changed library development. These factors … Read More
Standard cell, memory, and I/O library characterization is a necessary, but time-consuming, resource intensive, and error-prone process. With the added complexity of advanced and low power manufacturing processes, fast and accurate statistical and non-statistical characterization is challenging, creating the need … Read More
On-chip variation (OCV) is a major issue in timing signoff, especially at low voltages or in 20/16/14nm processes. For example, the graph below shows a 20nm inverter. At 0.6V the inverter has a delay of 2 (nominalized) units. But due to on-chip variation this might be as low as 1.5 units or as high as 3 units, which is a difference from… Read More
