2012
Iowa State University
Che, Xiaoyu
[EE 330
LAB REPORT #3]
Lab 3: Layout Versus Schematic
September 14, 2012
[EE 330
LAB REPORT #3]
Introduction
The goal of this lab is to introduce the concept of layout of circuits as well as design rules
checkers (DRC). We will draw a layout of an inverter and verify that the actual equivalent
circuit corresponding to the layout agrees with the original circuit schematic using a CAD tool
named layout versus schematic (LVS).
Steps
1. Layout view
a. Create a layout view of the inverter cell in lablib library.
b. Check grid settings.
c. Draw the schematic (draw rectangulars, create contacts and pins).
2. Checking for errors
a. Go to Verify→ DRC to check.
b. Go to Verify → Markers → Explain to debug.
3. Layout vs. Schematic (LVS) comparison
a.
b.
c.
d.
Do the extraction of the layout.
Hit Run run the LVS.
Find whether the net-lists match.
Locate a net on the extracted view.
Lab Result
Figure 1:
Iowa State University |Xiaoyu Che
1
September 14, 2012
[EE 330
LAB REPORT #3]
This is the schematic I draw. It is corresponding to the stick diagram of an inverter and the
width and spacing are according to the design rules so that there is no violation in the
schematic.
Iowa State University |Xiaoyu Che
2
September 14, 2012
[EE 330
LAB REPORT #3]
Figure 2:
From the si.out file we can see the net-lists match. The LVS is successful.
Iowa State University |Xiaoyu Che
3
September 14, 2012
[EE 330
LAB REPORT #3]
Figure 3:
This is the schematic after extraction. This diagram indicates that the system recognized the
MOSFETs and the pins we draw.
Iowa State University |Xiaoyu Che
4
September 14, 2012
[EE 330
LAB REPORT #3]
Conclusion
This time we successfully draw the layout schematic using the CAD tools. The design rules are very
important because we have to draw the schematic according to those standards so that the design
and fabrication can be successful. On the other hand we use DRC and LVS to verify the schematic.
This lab shows how an integrated circuit is designed and fabricated and will also be very useful in our
future labs.
Iowa State University |Xiaoyu Che
5