What is VLSI ?

Very-large-scale integration (VLSI) is the process of creating integrated circuits by combining thousands of transistor-based circuits into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed. The microprocessor is a VLSI device. The term is no longer as common as it once was, as chips have increased in complexity into billions of transistors.

The first semiconductor chips held two transistors each. Subsequent advances added more and more transistors, and, as a consequence, more individual functions or systems were integrated over time. The first integrated circuits held only a few devices, perhaps as many as ten diodes, transistors, resistors and capacitors, making it possible to fabricate one or more logic gates on a single device. Now known retrospectively as small-scale integration (SSI), improvements in technique led to devices with hundreds of logic gates, known as medium-scale integration (MSI). Further improvements led to large-scale integration (LSI), i.e. systems with at least a thousand logic gates. Current technology has moved far past this mark and today's microprocessors have many millions of gates and billions of individual transistors.

VLSI Verification

To reduce simulation time, system design and verification teams need to use a hardware-assisted verification system while reusing their established
behavioral test bench and verification environment.

To achieve a 10-fold leap in productivity, system design and verification engineers must begin designing at a higher level of abstraction.

To undertake comprehensive system-level verification, engineers must stress and validate their design in a scalable verification environment—one that
offers a high degree of control and visibility, applies system-level stimulus to the design, and verifies the performance and behavior of the integrated
system.

For effective system-level verification, engineers require a high-performance environment that allows access to hardware and software debuggers
while running various system-level scenarios using firmware, drivers, operating systems, and application software. Conventional simulation of designs
at RTL with embedded software at the system level is impractical and has performance limitations. Offering higher throughput, superior hardware/
software debug, and fast compilation

To ensure correct system verification, engineers must drive stimulus matching the specific protocols interfacing with their designs and check the design
response. They must also test the interface protocols under real-world operating conditions.