Tool Setup Cadence Asitic PDF

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Spiral inductor tool setup with cadence...

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ECE 712

ECE 712 Tool Setup and Use

Tool Setup, v3

B. Floyd, 1/03/2017

1) Log on to a Linux Computer Three ways are possible for accessing Cadence on Linux: (a) running Cadence on a Linux machine locally on campus, (b) remote access of an ECE Linux server (grendel), or (c) virtual computer lab (VCL) access of a windows machine at NCSU and then remote access of the ECE Linux server. If you are running Cadence at home on your own computer, you will obviously need to follow either steps (b) or (c). In particular, you will want to use data compression for the display so that Cadence can run across slower networks. Note that the “how-to” below assumes you are running Windows for your local machine. Mac or Linux users will follow a similar procedure. a. ACCESS METHOD 1: Go to an NC State computer lab and log into a Linux machine (i.e., EOS labs or ECE 1014 lab). You can then run Cadence natively. Note, though, that the local machine may still be too slow. As a result, you may want to “ssh –X” over to grendel.ece.ncsu.esu. b. ACCESS METHOD 2: If you are using your home or NCSU Windows machine: i. Run Xwin32 (2014) for the x-windows emulator (or some other xwindow emulator) 1. Download at http://www.eos.ncsu.edu/software/downloads/ 2. Validation number at https://www.eos.ncsu.edu/software/downloads/select-afile.php?download=337 ii. Start an xwindow terminal. This can be done one of two ways. 1. PuTTY: Run putty for a secure shell into a linux cluster (grendel.ece.ncsu.edu) a. Host name will be grendel.ece.ncsu.edu b. Connection type is SSH c. Go to the SSH category on the left and click “Enable compression”. This will compress the data traffic. Cadence sends a lot of display information for even the most minor commands. You need to have compression to allow this to work on slower networks. d. Go to SSHX11 and click “Enable X11 forwarding”. This will automatically set the display variable in your session to your local machine, meaning all new windows will be displayed on your local computer. e. You will probably want to save this session. f. Launch the session. To make sure that the display forwarding is working, you can type “xclock &”. You should see a clock window appear. If this did not work, your X11 forwarding is not 1

ECE 712

Tool Setup, v3 active. If needed, you can set the DISPLAY variable within the session to your local machine’s IP address (setenv DISPLAY xxx). 2. XWIN32. Xwin32 can also launch an ssh session. a. Right click XWIN32 in your system tray and launch X-Config. b. On left, click New SessionWizard. c. Give the session a name, such as grendel, and then select ssh. d. Enter host name as grendel.ece.ncsu.edu, then Next. e. Provide your login credentials, then Next. f. Select Linux for the type of host. This will select the command /usr/bin/xterm –ls g. Click Finish h. Now you will see the grendel session listed under My Sessions. Select this and click Edit. i. Go to Advanced. Select “Use Compression”. Also make sure the Disable X11 Forwarding is not selected. j. Launch the session. To make sure that the display forwarding is working, you can type “xclock &”. You should see a clock window appear. If this did not work, your X11 forwarding is not active. If needed, you can set the DISPLAY variable within the session to your local machine’s IP address (setenv DISPLAY xxx). c. ACCESS METHOD 3: Virtual Computer Lab (VCL). One of the difficulties with running Cadence remotely is having a fast enough network to handle all of the display information that Cadence constantly has to send to your local machine. The data compression mentioned above will help. Here is a third method which students have found to work quite well. i. Virtual computer lab allows you to reserve a computer on NCSU’s network with a desired set of applications for remote access. The basic idea is to reserve a windows machine, establish a remote desktop connection to that NCSU windows machine, start an x-windows manager, and PuTTY over to grendel (or another Linux machine). Display information is sent from the Linux machine to the virtual windows computer and then to your machine through the remote desktop connection. The key here is that the windows machine and the Linux machine are on the NC State network and have a fast network connection to each other and Cadence therefore runs quickly. Windows’ remote desktop connection handles the data compression efficiently. Students have reported this method works for even 1Mbps local network connections. ii. Go to https://vcl.ncsu.edu iii. Select “Make a Reservation” on the left menu iv. Select “Remote Access Apps (Win7)” from the drop down menu. You can choose either “now” or set a time for your reservation. v. You may have to wait for the reservation to be created. Once the reservation is ready, click “Connect!”. You will see an IP address for the remote computer. 2

ECE 712

Tool Setup, v3

Use this for the remote desktop connection. Also, you will need to log into this computer with the ID and password listed. vi. Establish a remote desktop connection. Go to All ProgramsAccessories Remote Desktop Connection. Provide the IP address from the above steps and give the log-in credentials. vii. Start an x-window emulator. For this VCL computer, this is Xming. viii. Launch PuTTY. You will then follow the steps above for the PuTTY ssh session to grendel. Note that you should still enable X11forwarding and data compression. 2) Setup Cadence Cadence can be used for the entire integrated circuit-design process (design, simulation, layout, verification, etc.). In 712, we will use it on homework and the project for schematic capture (i.e., netlist creation) and circuit simulation. Described below is the setup procedure to run the open-access version of cadence a. Log onto an appropriate Linux machine, set your display variable, as described above. b. Create a project directory for your design (e.g., ECE712) and then cd into this directory. c. Create an alias in your .mycshrc file, by adding the following line alias ece712setup source /afs/eos.ncsu.edu/lockers/research/ece/dk_cadence/gpdk090_v4.6/setup/setup.csh

d. e.

f.

g.

i. This will allow you to just type ece712setup rather than the longer command. ii. Note this is the same setup script used for ece511 Reload or source the .mycshrc file i. source .mycshrc Type “add cadence2015” i. This will set up all of the appropriate session variables and path statements for Cadence Type “ece712setup” i. This will create the .cdsinit and cds.lib files if they are not present, which are initialization and library definition files, respectively. You will need to run these scripts for every new session

3) Run Cadence and setup a library and cellview a. Start Cadence by typing “virtuoso&” b. Create a design library within cadence i. In the Library manager, select “FileNewLibrary” ii. Enter name for your library iii. Attach to existing technology library, gpdk090 c. Create a new cadence schematic cellview i. In the Library manager, select “FileNewCellview” ii. Select the library you just created and then give this a name iii. View name should be “schematic” d. For information on how to create a circuit schematic and run a basic simulation, please refer to the next tutorial… 3

ECE 712

Tool Setup, v3

4) Design kit a. We will be using the GPDK 90nm design kit from Cadence. NC State has a restricted license to use this kit, allowing students to use the kit. The terms of this license are such that you are not able to use this kit for anything else other than this class or learning how to use Cadence. b. Documentation for the design kit can be found in the following directory: /afs/eos.ncsu.edu/lockers/research/ece/dk_cadence/gpdk090_v4.6/docs

c. The spectre device models (i.e., BSIM3v3, etc.) are located in /afs/eos.ncsu.edu/lockers/research/ece/dk_cadence/gpdk090_v4.6/models/spectre

5) Run ASITIC to perform spiral inductor design and modeling a. This is an analysis and simulation tool for spiral inductors, developed by Prof. Ali Niknejad at UC Berkeley when he was in grad school. i. http://rfic.eecs.berkeley.edu/~niknejad/asitic.html b. Browse through on-line documentation for ASITIC i. http://rfic.eecs.berkeley.edu/~niknejad/doc-05-28-01/asitic.html ii. Look at Command Reference for more details on inductor creation and analysis c. I have installed asitic_linux into the directory listed below. You need to have this in your path (the ece712setup script will do this for you). i. /afs/eos.ncsu.edu/lockers/research/ece/bafloyd/bin/ d. Make sure that the asitic technology file is in the current directory (gpdk180.tek) i. The setup script will have copied this file into your project directory ii. This file should be placed in the directory from which you will run asitic. iii. You can read through this text file to see how the layers are defined iv. Note that metal layers are called m1, m2, m3, m4, m5, and m6 e. Run ASITIC i. Type asitic_linux ii. When prompted for the technology file, enter gpdk180.tek f. Create spiral inductors i. See the spiral-inductor tutorial for more details ii. Use the square or spiral for example. g. Analyze the inductor i. See the spiral-inductor tutorial for more details ii. Use the pi command for quick analysis, pix command for more detailed analysis iii. You can also examine the s-parameters of the spiral using the 2Port command

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