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INTRODUCTION TO VLSI and Y chart

 Very-large scale integration (VLSI) is the process of incorporating thousands of transistors into a single chip to create an integrated circuit (IC) . VLSI got its start in the 1970s, when complex semiconductor and communication technologies were being developed.  The microprocessor is a VLSI device.

A limited set of functions were performed by most ICs prior to the introduction of VLSI technology. An electronic circuit contains a CPU, ROM, RAM, etc. IC designers can integrate all of these functions into a single chip using VLSI.

Thanks to rapid advancements in large-scale integration technologies and device design applications, the electronics industry has grown at a breakneck rate in recent decades.Since the introduction of very large scale integration (VLSI) designs, the number of integrated circuits (ICs) used in high-performance computing, controllers, telecommunications, image and video processing, and consumer electronics has been increasingly growing.

End-users benefit from cutting-edge technologies such as high-resolution, low-bit-rate video and wireless communications, which offer a wide range of applications, computing capacity, and portability. This trend is expected to escalate, with major implications for VLSI and device/system design.

Y chart 

The design method is normally evolutionary in nature at different stages. It all begins with a given set of requirements . The initial design is created and reviewed against the specifications. When specifications aren't met, the design must be tweaked. If such an upgrade is either impossible or prohibitively expensive, a condition revision and effect analysis must be considered.The Y-chart (first introduced by D. Gajski) shown in Fig. demonstrates a design flow for most logic chips, using design activities on three different axes (domains) which resemble the letter Y. 

                   Figure : VLSI design flow in three domains (Y-chart representation).


The Y-chart consists of three major domains, namely:

  • behavioral domain,
  • structural domain,
  • geometrical layout domain.



                                   


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