PROJECT TITLE : CMOS 2:1 MUX Design and Implementation


NAME : A DEVIPRIYA
COLLEGE : CAMBRIDGE INSTITUTE OF TECHNOLOGY, K R PURAM, BANGALORE
EMAIL : adevipriya1900@gmail.com


ABOUT THE PROJECT :

Multiplexer (MUX) is one of the important components of communication system, to increase the efficiency of data transmission, to utilize the vast memory space of a computer in an effective way and to convert parallel form of data into serial form in telecommunication networks an efficient design of low power-delay MUX is required. MUX is a data selector with 2n input lines that selects one of several analog or digital input signals and forwards the selected input into a single output line. Multiplexer is a convenient module for the design of several dominant circuits. This paper proposes a narrative and efficient module of a CMOS based 2:1 multiplexer.


ABOUT THE CIRCUIT :

The given 2:1 MUX has two inputs(A,B), one selection input (S), and one output line(Y). Therefore, it can have only two achievable combination, i.e. 0,1. When selection input is ‘0’ then input line ‘A’ is preferred and is directed to the output, Y. Similarly, when selection input is ‘1’ then input line ‘B’ is preferred and is directed to the output, Y. CMOS based 2:1 MUX is build up of two sections namely, pull up lattice and pull down lattice. Pull up lattice is known as PMOS and pull down lattice is known as NMOS. In this model, PMOS device is connected to the supply voltage (VDD) and NMOS is connected to the ground (GND). Both PMOS and NMOS substrate is given to the source terminal (given to VDD in case of PMOS and GND in case of NMOS).


ABOUT THE WAVEFORMS OBTAINED :

The obtained waveform functions based on the 3 - Input binary truth table with the following combinations, 000, 001, 010, 011, 100, 101, 110, 111. The first input being 'S', second input - 'A', third input - 'B' and the output - 'Y' obtained for the combinations as as follows - 0, 0, 1, 1, 0, 1, 0 ,1. When S = 0, A = 0, B = 0, output, Y = 0, when S = 0, A = 0, B = 1, output, Y = 0, when S = 0, A = 1, B = 0, output, Y = 1 and so on.


INSTALLATION and USAGE of the eSim Tool :

Initially I felt it very difficult to understand and get started with eSim, sky130 as this was the first time me using the tool. At some point, I even felt lost thinking how to even proceed furthur. But, eventually I started to explore and felt comfortable with the tool and it's usage. It is very simple and self - learning tool for any person who wishes to start their journey with eSim having zero knowledge in it. 
The step by step procedure provided for our reference to install eSim tool and sky130 lib file was adequate. The errors generated almost seemed to be like impossible for me rectify and correct it. But, slowly I learnt and resolved everything. 
Now that I am done with the circuit simulation, designing part, I feel I can do a lot more.


SUPPORT :

The spoken tutorials available was acting like a backbone for my project, the mentor's support and help was very much sufficient to complete the project succesfully and the environment provided by the team was very friendly and comfortable. Functioning of the slack channel was again very much beneficial to clear all my doubts.
From my end, being a person with zero knowledge about the tool, design and simulation part, I completely enjoyed this journey. It was very much interesting and I learnt each and every bit of it. 


REFERENCES :

The following Author's paper have helped me to get my basics right and I felt it's very simple for any fresher to understand it and progress with it.

1.  Author - S. J. Anjum Aara. 
     Paper - Design and implementation of cmos and cnt based 2:1 multiplexer at 32nm technology.

2.  Author - E. J. S. Abirami, M. Arul Kumar. 
     Paper - Design and analysis of 2:1 multiplexer circuits for high performance.
