VLSI-2024

Portal for 2024 SIT batch being mentored at the Advnaced VLSI Lab.

TABLE OF CONTENT

• Resources
  • Reference
• Tasks & Assignments
• Projects
  • SPI-based TEMPERATURE MONITOR
  • Temperature and Humidity Monitor
  • A Simple 8-bit MIPS Microprocessor
• Electronic Design Automation (EDA) Software
  • Installing Icarus Verilog with GTKWave

RESOURCES

References

• [Mano] Mano, M. Morris, and Michael D. Ciletti. Digital Design: With an Introduction to the Verilog HDL. Pearson, 2012. [DBURL/s/54xsb46wcj6hdn9/ManoCiletti-DigitalDesignWithIntroToVerilog-5thEd-2012.pdf]. -- Classic text on digital theory with a nice intro to HDL.
• [West] Weste, Neil, and David Harris. CMOS VLSI Design: A Circuits and Systems Perspective. Pearson Education, 2011. [DBURL/s/ard8jntcpq1pt45/Weste-Harris-CMOS-VLSI-design-Pearson-4thEd-2011.pdf] -- An excellent reference on Digital VLSI design and VLSI design process as well.
  • [Web Companion] http://pages.hmc.edu/harris/cmosvlsi/4e/index.html
  • Annotated Chapters for Processing [DBURL/s/zxp1dnwknvpfz8y/Weste-JohnsMartin-CMOSprocessing-Layout-Highlight-annotate.pdf
• [Kang] Leblebici, Yusuf, Chul Woo Kim, and Sung-Mo (Steve) Kang. CMOS Digital Integrated Circuits Analysis & Design. 4th ed. McGraw-Hill Education, 2014. [DBURL/s/axtrki5yilzg8zs/Kang-CMOS-DigitalIC-4thIE-McGrawHill-2015.pdf] -- Classic text on CMOS VLSI Design.
• [Hodges]] Hodges, David A., and David. Analysis And Design Of Digital Integrated Circuits, In Deep Submicron Technology (Special Indian Edition). Tata McGraw-Hill Education, 2005. [DBURL/s/olc3j7hkarlwila/HodgesJackson-DesignAndAnalysisOfDigitalIC-3Ed-McGraw-2005.pdf]. -- Another classic text on CMOS VLSI Design.
• [Palnitkar] Palnitkar, Samir. Verilog HDL: A Guide to Digital Design and Synthesis. Prentice Hall Professional, 2003. [DBURL/s/h5qxwwff3qxl58z/PalnitkarSamir-VerilogHDL-2ndEd-2003.pdf]. -- Classic text on Verilog.
• [Mishra] Mishra, Kishore. Advanced Chip Design: Practical Examples in Verilog, 2013. [DBURL/s/qb3rm97rqvri6my/MishraKishore-AdvancedChipDesign-Verilog.pdf]. -- Lots of Verilog examples.

TASKS and ASSIGNMENTS

• [23 Dec 2022]:
  • Research and understand the I2C protocol. You can start with some of the links provided below.
  • Create a Verilog model for the DHT20 temp & humidity sensor.
  • Continue with the Verilog lessons from chipverify.com
• [21 Sep 2022]: Follow the first 8 lessons in this GitHub page to get familiar with and improve your skill in using Unix/Linux commands. You can use any Linux machine (webinal or your Virtual Box) to complete the assignement.

PROJECTS

SPI-based TEMPERATURE MONITOR

This project will aim at design and immplemention of a SPI-based temperature monitor. The students will design a controller in Verilog to read the data from the sensor (LM70) using the industry-standard SPI protocol, convert the data to a human readable format (deg-C) and drive a set of 7-segment display to display the data. In order to test the Verilog code in realtime application, the Verilog code will be synthesized into a Xilinx's Spartan FPGA board. This will allow the students to test their Verilog code in real time.

SOME USEFUL LINKS

• An easy-to-read SPI tutorial from sparkfun
• Datasheet: TI SPI-based temperature sensor LM70
• Technical Reference: Xilinx Spartan-6 FPGA Development Board

❗ TASKS: ❗

• 1️⃣ Convert the shift register code to a compact format like this shift_reg <= shifte_reg<<1;
• 2️⃣ Latch the 8-bit output from the LM70 to outreg[7:0] at the end of read cycle and verify you the value is the same as set in the temperature sensor.
• 3️⃣ Follow chipverify.com excercises till the Behavioural modeling section. Now you can use iverilog to complete the assignments.

I2C-based TEMPERATURE and HUMIDITY MONITOR

This project will aim at design and immplemention of a temperature & humidity monitor. The students will design a controller in Verilog to read the data from the sensor (DHT20), convert the data to a human readable format (deg-C and Rh-%) and drive a set of 7-segment display to display the data. In order to test the Verilog code in realtime application, the Verilog code will be synthesized into a Digilent Arty A7 FPGA development board. This will allow the students to test their Verilog code in real time.

SOME USEFUL LINKS

• An easy-to-read I2C tutorial from sparkfun
• An detail IC implementation of a I2C controller
• Datasheet: DHT20 Temperature & Humidity Sensor
• Arty A7 FGPA Development Board Resources

A SIMPLE 8-bit MIPS MICROPROCESSOR

For this project we will design and immplement a 8-bit subset of the MIPS microprocessor architecture as outlined in [Weste] Chapter 1.7 as an example case study. The major development steps for this project will be:

• Study chapter 1.7, understand it well and prepare a short presentation summarizing the project.
• Create a behavioural model in Verilog of the whole microprocessor and test it with a machine code of a simple program.
• Create structural models of each sub-system of the processor using Verilog structural flow using a basic set digital gates.
• Verify each subsystem and the entire processor using the structural models.
• Design, layout and characterize each of the digital gates used in the processor using SKY130 technology.
• Back annotate the chracterized delays into the Verilog models and do timing checks and find the highest frequency of operation.

ELECTRONIC DESIGN AUTOMATION SOFTWARE

INSTALLING ICARUS VERILOG with GTKWAVE

In this section we will demonstrate on how to install the open-source Verilog simulator Icarus Verilog (iverilog) and view the result using an open-source viewer GTKWave.

SOME USEFUL LINKS:

• iVerilog creator Steve Icarus's document page

The following instructions are for iverilog and gtkwave from a standard Ubuntu 18.04 repository:

• sudo apt update && sudo apt upgrade -y : To update your distribution.

• sudo apt install iverilog

• sudo apt install gtkwave

• Now let's compile a simple verilog module and it's testbench: mydut.v and tb_mydut.v. An example contnet of the Verilog code is given below.

  • Create project directory say mkdir -p ~/iverilog/test and cd to that directory.
  • iverilog -o tb_mydut.vvp mydut.v tb_mydut.v : Compile the verilog codes and create an output tb_mydut.vvp
  • vvp tb_mydut.vvp : Convert the compiled output to a VCD format for GTKWave.
  • gtkwave dump.vcd : Note: the filename dump.vcd is assumed to be in tb_mydut.v

• If you want to execute the first two commands as script, you can add the first two commands to a file called say run:

iverilog -o tb_mydut.vvp mydut.v tb_mydut.v
vvp tb_mydut.vvp

• Now mamke the file executable by typing the follwoing command: chmod +x run

• And from now on, you can simply execute the script by typing ./run

• Example content of mydut.v:

// Simple DUT with NAND expression 
module mydut ( input A, input B, output Y);
  assign Y = ~(A & B);
endmodule

• Example content of tb_mydut.v :

module tb_mydut;
  reg A;
  reg B;
  wire Y, Z;
  
  mydut dut0 (.A(A), .B(B), .Y(Y));
  
  initial begin
    // Dump waves
    $dumpfile("dump.vcd");
    $dumpvars(1);
    
    A <= 0;
    B <= 0;
    #2 
    A <= 0;
    B <= 1'bx;
    #2
    A <= 1;
    B <= 1'bz;
    #2
    A <= 1;
    B <= 1'bx;
    
   #2 $finish;
  end
endmodule

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