We are conducting a basic VLSI course. Around 16 participants from in and around Auroville are coming in to learn. We are only focusing on Digital layout and understanding basic concepts.
Give an introduction to CMOS technology and fabrication process. Give an intro to CMOS Transistors and it’s working. Introduce people to stick diagrams.
- Introduction to VLSI technology.
- Introduction on CMOS transistors and working.
- Demo on LT spice simulation tool.
- Introduced CMOS Inverter and ask participants to simulate an inverter in LT spice.
- Showed a video on fabrication process and manufacturing a chip.
- Introduced stick diagram and how it helps to get started with layout. Participants drew a stick diagram for an Inverter.
- Introduced magic layout tool.
- Helped them to login to our central server through VNC. This helped them to avoid installing magic in their laptops. We haven’t figured out a way to install in windows so far, but Magic sort of works fine in Ubuntu platform.
- Showed top view and cross section of a CMOS transistor. This helped them to understand the fact that layout is all about top view of the devices.
- Participants laid out an invereter using magic.
- Once that was completed we showed them to extract and create a netlist. Netlist helps us to understand the connection and cross check whether the layout we laid out is correct or not.
- Introduced NAND gate
- Laying out NAND gate. (Note: We gave a circuit diagram for a NAND gate)
- Extracting NET list and with the same netlsit draw the schematic usind the netlist.
- Whoever completes should layout a NOR gate and repeat STEP 2 and 3.
- Introduced to gates. (OR, AND, INVERETER, NAND, NOR and EXOR)
- Understand the truth table for all gates.
- Introduced few rules like Involution law, Idempotency law and De Morgan’s law
- Task 1: Using NAND gate create OR, AND, INVERETER and EXOR. Draw schematic and derive the logic for the same.
- Task 2: Build those gates using DM74S00N and bread board and test whether their logic were appropriate.
- Intorduced Hierarchy. Showed how to import models that can be used to create complex layouts.
- Task: Layout an XOR gate importing the NAND gate built in the previous classes
- Introduced IRSIM
- Task 1: Test different layouts with IRSIM
- Task 2: Whoever didn’t complete XOR should complete XOR and test it out using IRSIM
We wanted people to see a real layout and at the end of the course, layout a micro processor.
- Showed them a layout of a real chip.
- There are three main blocks necessary for a micro processor. ALU unit, Memory and Counter. We used full adder for ALU and Flip flops for every bit for a memory and counter.
- Task: Layout a micro processor