RTL Logic Synthesis Tutorial

The following Cadence CAD tools will be used in this tutorial:

RTL Compiler for logic synthesis.

Computer Account Setup

Please revisit Simulation Tutorial before doing this new tutorial.

In order to setup your environment to run Cadence applications you need to open an xterm window and type:

. cadence2009

Running the Cadence logic synthesis tools

Now you should be able to run the Cadence tools. Never run Cadence from your root directory, it creates many extra files that will clutter your root. Instead please create a directory (e.g. cadence, you should have this already) and another directory for the design (e.g. tutorial, should have it) and finally one for the synthesis files (e.g. synthesis):

cd cadence cd tutorial mkdir synthesis cd synthesis

For this tutorial you will need a few extra files, please download the following file in the synthesis directory (this is a script that you will have to edit for other designs):
rtl.tcl

from:
http://www.ee.virginia.edu/~mrs8n/soc/files

The command rc -gui (no &) starts RTL Compiler version 8.1 (2009) in the foreground and you should get the rc startup window:

rcstart

The window has three areas:

Menu Bar (top)
File Browser (left)
Schematic Browser (right)

Unlike other GUI interfaces, the console this time is the initial window from which you launched rc (that's why it had to be launched in the foreground). Please try to familiarize yourself with the main window, click on the menus, etc. For more information on the various Cadence tools I encourage you to read the corresponding user manuals. You can get to the manuals by pressing Help -> Reference Manuals on the right of the Menu Bar. Spend some time browsing the manuals to understand what is available (a lot!). During the semester you will have to look for information in the on-line manuals to complement the (limited) info given by these tutorials. Actually you can think of this tutorial as a subset of the one available under help!

Now we need to run the script that you copied from the files directory so go to File -> Source Script from the File menu of the Menu Bar. Click on rtl.tcl, then OK:

loadscript

Your console should run for a brief time and you should get a success message:

success

Now your GUI window should show a netlist on the right side, and if you click on HDL, the source code on the left side:

guiafter

Try some of the menu options, for example you can see what library standard cells were used in the synthesized netlist by going to Report -> Netlist -> Mapped Gates...:

instances

Another important tool is the design browser, go to Tools -> Object Browser...

vdir

Finally, you can close the GUI by going to File -> Exit and you can now analyze the result of the synthesis in the file accu_synth.v that you can use for simulating the netlist and for subsequent place and route using Encounter:

accu_synth

Congratulations, this is the end of the Logic Synthesis Tutorial.