Posts

Adding more cells into our library

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In the previous post, we added an inverter, a 2-input NAND, and a 2-input NOR into our library.In this post, I shall add a few more cells into my library. I am choosing to add these cells mainly because, in my experience, these are the cells that are mostly used by the tools to synthesize your behavioral logic to a structural description. This is not the perfect library of cells, and I will want to add more custom cells in the future. These cells are more like a template upon which I will want to build my library. There is this wonderful paper online which argues that a library with 20 cells can perform almost as well as a library with 400 cells. It's called Compact yet high-performance (CyHP) library for short time-to-market with new technologies Read through this paper once before choosing to build your library.  The cells I will be adding to my library are: 1. TIEHI 2. TIELO 3. AOI21 4. OAI21 5. MUX2 6. NAND3 7. NOR3 8. XOR2 9. XOR3 10. XNOR2 11. X
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Chapter 2: Creating Schematics

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This post covers Chapter 3 of the book, not word to word of-course! Fire up Cadence with cad-ncsu . From the (Command Interpreter Window) CIW, choose File->New->Library Give you Library a name, I'll call mine Lab1. Select the "Attach to an existing technology library" under Technology File. Hit "OK". This pops-up another window with your New Library and a list of libraries to which you can attach your newly created library. I chose the UofU_TechLib_ami06 technology Library. You can choose a library of your choice or one as instructed by your instructor. Hit "OK". Go to the Library manager window. If you can't view the library manager, then from the CIW go to Tools->Library manager. The column in the left in the Library Manager named "Library" has a list of all the libraries you have access to. A Library, just like a typical library, has a collection of "views"/"cells" which you borrow into your de
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Chapter 1: Setting up CADENCE

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CADENCE and SYNOPSYS are very expensive CAD tools. These are the tools (if not all!) that engineers use to build all the beautiful, cutting edge circuits you see out there. The software suite should be installed on your University, School or workplace computers, and you should be licensed to run these tools. In this post, I'll guide you through setting up the Cadence suite and how to get it running. At some point in the design flow, the tool might through a nasty bug at you which you might not be able to fix, infuriating you. When this happens, sit back, go for a walk, eat a nice dinner and then get back to solving the bug. Yes, the tools are very picky. Remember, these tools are what we use to build circuits with a billion transistors , and so it has every right to be picky! Open a terminal and follow on with these commands. 1. Go to your home directory. cd /home                                                                       or cd /home/USER_ID            (if you h
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Authors Note

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Hi, My name is Harikrishna Kambala Subramanyam. I'm a graduate student in Electrical and Computer Engineering at the University of Utah. I'm most interested in the field of VLSI (Very Large Scale Integrated Systems) and would love to work in mixed-signal designs. If you have taken/are taking any analog or digital circuits design course, you might have come across the term CADENCE. Chances are you might also be using one of it's many tools to design your circuits, simulate them, test them or layout your design. CADENCE is one big CAD (Computer Aided Design) Tools Suite, and it integrates many smaller tools to give a "one stop shop" solution to all of your circuit design requirements. In the following posts, I shall explain all the design steps and the small nuances in designing digital circuits by using the CADENCE tools. The book I shall be referring to is called "Digital VLSI Chip Design with Cadence and Synopsys CAD Tools" by Dr. Erik Bru
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