Very Large Scale Integration or VLSI is the current generation of computer microchips. The term is used for the technology used in microchips that helps fit hundreds of thousands of transistors into a single chip.
Jack Kilby of the Texas Instruments created an IC in 1958. It was a crude unit with many issues. He was able to create all the parts from the same block and the metal layer worked as the connector. This eliminated the need for using different components and wires that would otherwise require manual assembling.
The circuits in the first ICs were smaller and the process of manufacturing was automated. The idea of integrating all the components and creating a single semi-conductor wafer was formed during the 1960s and led to the creation of the small scale integration circuits.
The medium scale integration circuits were created in the late 60s and the large scale integration circuits followed in the 70s and 80s. By the time VLSI technology was developed, it became possible to bring millions of transistors on the same chip.
The first chips could hold not more than two transistors. Gradually, more transistors were added while more functions and systems were added. The initial ICs had a few devices and they could create just a few logic gates for a device. The design of the VLSI is based on the algorithm that describes the behavior of the chip. The Finite State Machines or FSMs are defined by the design evolution implemented into the functional modules.
The modules are carefully mapped onto the surface of the chip using CAD tools. This helps in achieving minimal signal delays and interconnect area delays. In the last stage of development, the chip id defined based on logic gates through the use of routing program and placement of the cell.
The design styles in VLSI are of the following types – Field Programmable Gate Array, Gate Array Design, Full Custom Design and Standard Cells Based Design. The design is used extensively in communication technology and multimedia.