What is VLSI & Why we Need VLSI ?

As we all know VLSI stands for Very large scale integration. Very large scale integration  is the process of creating an integrated circuit by combining thousands of transistors into a single chip. Now the question comes why we need VLSI???? So the answer is that one of the most characteristics of information service is there increasing need for very high processing and band width. The other important characteristics is that the information service  tend  to become more personalized, which means that the information processing device must be more intelligent and also be portable to allow more mobility.

VLSI is mainly classified in two classes.

 VLSI back end – VLSI back-end includes Route, place and floor planning. Back end includes development and fabrication part. It is  too costly and time consuming process.Physical designing and layout refers to back end.

 VLSI front end – VLSI Frontend includes designing and testing part.  It uses Verilog and HDL, VHDL .RTL designing , minimizing delay and simulation refers to Front end.

VLSI

There are two important   steps . VLSI design and  designverification. VLSI design refers to  the  designing of  VLSI circuits and its implementation . Design verification is use to test the design  and verify us that the given designing is working properly or not.
 

Now, we should move towards physical and digital design of VLSI. Both are very important part of VLSI.

Digital design is divided in three steps. First is BEHAVIORAL, second is STRUCTURAL and third one is PHYSICAL design. BEHAVIORAL describes the algorithm, STRUCTURAL describes component and their connections,  PHYSICAL describes how circuit built.

In standard design cycle physical design  comes after  the circuit design. Physical design includes both design and verification and validation of layout.  At this step circuit representation is converted into geometric representation. 

                                                                                                                 

                                                                                                       Author - Trisha Jain
                                                                                                  (Intern at Silicon Mentor) 

What is an Image and Image Processing?

IMAGE:

An image is a still representation of any worldly physical thing,be it a person or an object.It  depicts our  visual perception.In Digital representation an image is a rectangular grid of pixels.An image,therefore,has a definite height and width measured in pixels.

Image may be 2-D (a photograph) or 3-D (statue or hologram). It may be volatile (like the one formed in front of a mirror) or fixed (like the one recorded on a textile).

PIXELS:

Pixels are the smallest unit of an image or the building blocks of an image,similar to the cells that make up a human body.

A Pixel is a square shaped structure.Each pixel has some color intensity. A pixel conveys information about the image in the form of the colour intensities that it consists of. The colors talked about here are the primary colors: RED,GREEN,BLUE. All other colors are formed from these colors only.

Color intensities in a pixel are  represented in the form of bits.Each of the three RGB colors have intensities in the range 0-255, i.e., 8 bits are used for each color in a single pixel. In addition to these (8*3=) 24 bits, 8 bits are used for transparency in an image.

The higher the number between 0 and 255,the more will be the intensity of the color and the brighter the color will be.

REPRESENTATION OF AN IMAGE:

An image is represented in the form of pixel values. Suppose an image has 1024 pixels row wise and 1024 pixels column wise, then the size of that image will be 1024x1024, and total number of pixels will be (1024*1024=) 1048576. 

TYPES OF IMAGES:

Colored Image: An image having matrices for all the three colors .

Monochrome Image: An image having only one color.

Black and White Image: An image having matrix of only binary values i.e.,0 and 0 showing black color and 1 showing white.

Gray scale Image: An image having shades of gray only (neither complete black nor complete white). The new matrix in this type of image is formed by taking the average of the three color intensities.

 

IMAGE PROCESSING

Image Processing includes different processes that can be performed on an image in order to enhance the quality of an image. These processes can be:

1.Removal of noise.

2.Extraction of only text from the image.

3.Changing the intensity of an image.

4.Adjusting the contrast of an image.

What is Etching and its effects?

Etching :

Etching is the process in which strong acid is used to remove the unprotected parts of a metal surface as after thin film deposition on the wafer surface, they are removed directly from the wafer surface and desired pattern of the of the film is left on the wafer surface.

Etching can be done either in wet or dry environment. In wet etching etchant solution, which is used is in liquid form and the wafer is usually immersed in the etchant solution and the exposed material is etched away by the chemical process. In dry etching etchant solution, is in gaseous form in plasma. Here etching takes place by chemical and physical process. Hence dry etching is also called Plasma Etching.

Etiching

Effects of Etching:

Ferric Chloride is widely used etchant and is commonly used in chemical etching. FeCl₃ produces a smooth side wall after etching and FeCl₃ is commonly used to etch white metals such as iron and nickel based alloys as well as Zi, Al, Mg etc. Another advantage of using FeCl₃ is that it can be regenerated within process. Although FeCl₃ increases regenerating capability but on the other hand it increases volume of the etching solution.

Cupric Chloride is most commonly used etchant as it is capable of continuo us regeneration at a steady rate condition. It has etch rate half than FeCl₃ but than also it is most commonly etchant. Because of etching surface imperfection occurs due to uneven chemical attack of etchant solution.

Author - Somya Bisaria

(Intern at Silicon Mentor)

Analog Prototyping of Neural Networks And its Applications

 Introduction

As we are moving towards a revolutionary era of technology so there is a requirement of precise, predictive and accurate analysis which may be fulfill by neural networks.

Neural networks, as the name suggests, is analogous to human brain which have highly interconnected neurons. Different Combinations of transistors formed neurons which are interconnected to design neural networks. These neurons are also termed as processing elements.
Neural networks can efficiently solve a complex problem. By understanding the relationship between the different input data theoretically unknown solution can be found in problem space. Generally the output of neural networks is not predictive.

Now let us take an example of neural networks i.e. “winner takes all circuit”. In WTA circuits many inputs are given to the different neurons and these neurons compete with each other and give output according to neuron having highest input current/voltage.

Application of Neural Networks

There are various applications of neural networks in today’s industries, some of them are as follows:

•    Pattern recognition : neural networks play a vital role in pattern recognition. Networks is design according to the input pattern and it gives the output corresponding to associated pattern

•    Data validation : several data is given as input at different layers of neuron but result come out according to the input data validate by neural circuitry.

•    Forecasting : By analyzing the output at different inputs forecasting can be done i.e. it can be determine that which input gives desired output.

•    Target marketing : if forecasting can be done then way to achieve target can be analyzed easily. It becomes possible to know that which input leads target output.

•    Risk management : with the help of neural networks chances to choose wrong input becomes quite less.

Neural Networks

Author - Jyotishna Bansal

(Intern at Silicon Mentor)