All layout in this class will use the magic technology file SCN3ME_SUBM.30, which can be specified on the command line by saying: magic -T SCN3ME_SUBM.30.

Part 1 (tutorials). For the first part of this lab, read and complete the magic tutorials. Every group member should complete these tutorials. The commands you will learn will save you many hours of effort during the rest of the class. The tutorials that you should read are #1, #2, #3 (pages 1-5), #4, #6, #8. They are available in the online documentation for magic.

Part 2 (layout). Use the layout editor magic to draw a chain of three inverters with inputs labelled i1, i2, i3 and outputs o1, o2, and o3 respectively. Connect o1 to i2 and o2 to i3. Make each inverter as small as possible (in terms of the width and length of each transistor), and your overall layout as compact as possible. The width of each transistor should be at least 4 lambda.

Save your design in file inv.mag (do not use hierarchy for this lab), and extract your circuit (tutorial #8) to generate file inv.ext.

Part 3 (CAST files). Write a CAST file called inv.cast that describes the three inverters using production rules. Your file must import 474/globals.cast which contains the definition of global symbols. As an example of the way CAST supports production rules, a two-input NAND gate would be written as follows:

define nand2() (node a, b, c)
{
  prs {
    a & b -> c-
   ~a | ~b -> c+
  }
}

Define threeinv() (node i, o) that contains the three inverters you designed in part 2, with i connected to i1, and o connected to o3. Simulate this CAST file with IRSIM by creating a test file test_inv.cast that instantiates a copy of threeinv. Save your IRSIM test script in inv_cast.cmd.

Instructions on simulating CAST files with IRSIM can be found here (these are the same instructions used for ECE/CS 314). Make sure you set Vdd and GND to the right values in the IRSIM test script.

Part 4 (simulate layout). Generate files inv.sim and inv.al by saying ext2sim inv.ext. Simulate your circuit using irsim by saying: irsim ami30.prm inv.sim inv.al. Save the test script for your circuit in file inv.cmd.

Your layout should use Vdd! to label the power supply, and GND! to label ground. Ensure that the substrate is connected to the appropriate power supply by using substrate contacts (material name: psc and nsc for p substrate contact and n substrate contact). To see the substrate, place the box over your layout and say: :cif see CWN or :cif see CWP to see the different wells. To erase the white feedback paint, use the command :feedback clear.

Make sure you set Vdd! and GND! to the right values in the IRSIM test script.

Part 5 (lvs). You must also check that your physical layout implements the production rules in your CAST file by using the program lvs. lvs is a tool that checks whether the extracted layout matches production rules.

To run lvs, you need to extract your layout and also generate a production rule file from your CAST files. To generate a production rule file from your CAST file, say:

cast2lvs inv.cast threeinv > threeinv.prs

lvs -dDE inv.ext threeinv.prs

For lvs to match your layout against production rules, the names you use for nodes in your layout MUST MATCH the names you use in your CAST file. In addition, cell ids must match the names used to instantiate defintions in CAST for hierarchical layout.

Part 6 (well-plug checking). You must run the following on each .mag file that has transistors in it (in this case just inv.mag):

wellcheck file.mag

• The lab number and the names of the group members and their CSL login ids.
• A picture of your layout (use the :plot postscript or :plot pnm command in magic)
• The input to output delay for your circuit for both low to high and high to low changes in the output. Use IRSIM to measure this delay. Report it for both the extracted layout and the layout simulated from CAST files.
• The dimensions of the bounding rectangle of your layout in lambda. (i.e. your layout has area x lambda by y lambda), and the area of your layout in lambda square.

Electronic Submission. We will be using the CMS course management system. Create a submit.tar.gz file (use the tar command; man tar has the options) that contains:

• inv.mag, inv.cast, test_inv.cast, inv_cast.cmd, inv.cmd

• Magic home page
• IRSIM source

You can always use VNC/ssh to connect to the lab remotely and work from home.