Homework_8 -- Automatic Leafcell Generation

Written on 11/12/02 by Chandra Tan and D. Bouldin
Revised on 10/01/09 by D. Bouldin
Revised on 11/24/09 by D. Bouldin
Revised on 10/13/10 by D. Bouldin
Revised on 09/14/11 by D. Bouldin


Tutorial: Automatic Leafcell Generation Using ProGenesis


This homework involves automatic leafcell generation using ProGenesis.

Compaction (pdf).

So, we first login to ada3 and copy the following tar file.

cp ~bouldin/webhome/protected/651-hw8.tar

tar -xvf 651-hw8.tar

cd 651-hw8

In general, we begin by drawing a schematic and performing the 
pre-layout simulation with Spectre.  In our case, we already
have the schematic for "invx1" in the OSU_AMI06 library
which has been simulated successfully using Spectre.

Edit the Spectre net-list, invx1.net to use "TN" for nfets 
and "TP" for pfets as preferred by the Prolific tools to produce invx1.sp.

Next, we will invoke the Prolific leafcell generator 
to layout this net-list using a process-dependent 
tech-file that includes the SCMOS_SUBME (lambda=0.3) 
design rules along with constraints.  This produces
a layout which conforms to the 100-lambda standard-
height cell format for the AMI06 process:

Note:  The Prolific tools work on ada1-ada4.
       However, you may need to add in your home directory
       an executable (license manager) file named ".flexlmrc"
       with the contents:

       PROLIFIC_LICENSE_FILE=27000@prolific-lic.eecs.utk.edu

progen -t tech/ami06.db -i invx1.cel -o invx1.agd -g

Alternatively, you can omit the "-g" option and then type:

proview -t tech/proview.tcl invx1.agd

which allows you to view the final layout: invx1-agd.jpg.

Another example is NAND2X1.

Additional examples are in more-netlists.txt.

Here are the commands I used:

prospin -l invx1 invx1.sp
progen -t tech/ami06.db -i invx1.cel -o invx1.agd > invx1-ada3.log
tail invx1-ada3.log > invx1-ada3-log
proview -t tech/proview.tcl invx1.agd

Note: To perform transistor folding using Prolific, 
just include the "-f" option:

prospin -f -l inv inv.sp 

A layout w/o folding may be too high while one with folding is okay.

Prolific-Overview (34 pages).  

ProGenesis_Guide (463 pages).  

Prolific-Comparisons-Project (26 pages)

Manual vs. Auto Comparisons (11 pages)

Cadabra-product

Cadabra User Guide (430 pages)

Cadabra-paper

Cadabra-presentation

Cadabra vs. Progenesis (2005)

FreePDK Design Flow


Part A: Repeat the tutorial above for NAND2X1
Capture the proview layout and compare it to the 
OSU_AMI06 layout view.

Compare the widths of the resulting layouts: NAND2X1-ada3-log to 
OSU-NAND2X1 (7.2 x 0.3 = 2.16 microns)

Part B. Repeat Part A using alternate tech files.
Two additional tech files are available in the tech subdirectory:

ami06_LP.db and ami06_tall.db

To determine the difference between the three tech files, type:

diff ami06.db ami06_LP.db

diff ami06.db ami06_tall.db

Repeat Part A using these additional tech files and compare the results.

Part C. Execute the Cadabra Tutorial

Part D. Repeat Part C for your unique circuit in HW6-D.

Use Cadabra to implement your unique hw6d circuit using freepdk45nm.
Post your results on your protected webpage and compare them to your hw6d results.