Lab 1 - EE 421L Digital Integrated Circuit Design, Fall 2020

Author: William Wherry

Email: wherrw1@unlv.nevada.edu

8/29/2020 

  

Lab description:

Laboratory introduction, generating/posting html lab reports, installing and using Cadence.


Prelab work:

   

Before lab 1 we were tasked with reviewing the material in the tutorial for editing webpages to get us familiar with setting up our lab documents on our web pages. After tinkering with Komposer, I managed to created a mockup lab report seen below.

   

fig 1

 


Laboratory Work:

This first lab will go through the first part of Tutorial 1 seen here
Go through Tutorial 1 up to the following image (the 25th image in the tutorial).

   

After setting up all of the files necessary using Tutorial 1, you can start up Cadence from MobaXterm by first navigating to the CMOSedu directory using "cd CMOSedu," then typing virtuoso &. It is important to navigate to the CMOSedu directory first or Cadence will not work. Once Cadence opens, the Library Manager should appear and we need to create a new library by selecting "File" and clicking "New",, then "Library." The name of this new library is called "Tutorial_1".

   

fig 2

Now that the library is created, we need to make sure Cadence knows where it is located. If we navigate to the cds.lib file in the CMOSedu directory and open it with the text editor, we can see lines of text that tells Cadence where our libraries are located. Thankfully, since we created the Tutorial_1 library in cadence, it automatically directed the cds.lib file to our library, so nothing more needs to be done. However, if other libraries are to be manually added to Cadence we will need to use the DEFINE command line to point to our libraries we wish to use.

   

fig 3

   

If we look at the Library Manager in Cadence again, we can highlight Tutorial_1 in the list, then select File->New->cell view and create a new schematic. For this lab we named it "R_div." Hitting "ok" will open an interface that will allow you to add components to a blank schematic.

   

fig 6

   

Pressing the "i" key or using Create->Instance in the menus will allow you to select and add components to the schematic. We wish to make a voltage divider, so we need some resistors, a voltage supply and a designated ground.

   

fig 7

 

Values of components can be changed by selecting them and pressing "q" to bring up the properties menu.

   

fig 8

   

Wires can be added with the "w" key or by pressing the button on the top menu bar. You can also name nodes by selecting the tool from the menu bar. Ground can be added by pressing "i" and typing "gnd" in the box labeled "cell." This is a common part, so it doesn't need to be navigated through the menus to find.

   

fig 9

   

Voltage supplies can be found through the same menus as the other components. Once the circuit is complete we are ready to simulate it in the Analog Design Environment (ADE). 

   

fig 10

 

We start it up by selecting Launch->ADE L in the top menu bar. A new interface will appear that allows us to set up our simulation environment. 

   

   

fig 11

   

The first thing we have to do is make sure the correct simulator is selected by navigating through Setup->Simulator/Directory/Host and selecting "spectre" as the simulator if it is not already set to that. Next we have to run a transient analysis, so we select Analyses->Choose and pick "tran" from the list, with a stop time of 1 second. Since we want to measure the input and output nodes of our circuit, we can select Outputs->To be plotted-> By selection and then manually click on each node in our circuit to be measured in our analysis. 

 

fig 12

   

We click the green button to begin the simulation and the results should appear in a pop up window.

   

fig 13

   

With our results displayed and recorded, we have completed Tutorial 1 and our work in this lab with Cadence software.

     


     

Next, we must backup our work. I chose to backup my work by first downloading the Tutorial_1 folder using MobaXterm. This takes it from the server and places it on my home computer. I similarly download the lab reports we work on by copying them from our ftp server and applying the same techniques below to back those up. 

   

fig 15

   

Next, I navigate to the location that I downloaded it and send it to a compressed .zip folder.

      
fig 16

   

Finally, I email the zipped folder to myself. In case I ever need it again I can simply download it from the email that I sent myself.

   
fig 17

fig 18

   
   

With our simulation completed, recorded and backed up (as well as the lab report), Laboratory 1 is concluded.

   

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