What Are The Steps Involved in VLSI Design?- Explained in Detail

 

The VLSI Design is associated with designing semiconductor devices and circuits and small-footprint systems with embedded components. The technique of building ICs (Integrated Circuits) by joining millions of metal oxide silicon (MOS) transistors into a single chip makes VLSI systems unique.. 

What Are the Steps in VLSI Design Flow – A Brief Explanation

The RTL netlist is transformed through the physical design process into a layout that can be produced). Additionally, as demonstrated below, other phases are involved in transforming a netlist into a manufacture-able layout:

• Partitioning: It entails breaking down a complicated circuit into manageable-sized subsystems (also known as sub-blocks) with the least possible number of connections between each subsystem.
• Floor Planning: Each block's shape and approximate location on the silicon chip will be determined in this step. Each block's pin placements will be determined so that future linkages between these blocks can be routed easily.
• Placement: The precise placement of various sub-blocks will be determined to ensure enough room between different blocks so that the connections wires and VDD and Ground distribution systems (GDS) may be routed without creating any congestion.
• Clock Tree Synthesis: Millions of flip-flops will be dispersed throughout the complicated circuit's floor layout and placement on the silicon chip, causing all flip-flops to experience different clock signal transmission delays. 

The clock will arrive at or reach only some of the flip-flops simultaneously. Clock skew is the discrepancy between the clock signal's arrival times at these flip-flops.

Furthermore, it must be ensured that the clock signal reaches several flip-flops with no or slight skew. The clock will almost always reach different flip-flops at the exact moment, thanks to CTS. 

To ensure that all of the wires in the clock distribution network have the same length, any one of the conventional Tree topology structures will be included in the design during the clock tree synthesis process.

• Routing: In this step, linking wires between different blocks will be routed to ensure that their lengths are kept to a minimum to match timing specifications and prevent the chip area from expanding. In addition, proper routing guarantees no congestion hotspots on the chip, reducing the likelihood of manufacturing errors.
• Static timing analysis: To validate the timing performance of the chip and ensure that it will meet timing requirements like the maximum frequency of operation. The design should work at the desired frequency without any setup and hold time violations, static timing analysis will be performed on the final routed netlist. This will represent/mimic the final layout of the chip that will be fabricated.

The placement and routing will be optimised to improve timing and remove violations if the timing requirements are not satisfied or if any installation and hold period violations are found.

The physical layout will be retrieved after the timing criteria are met. These layouts will be used during fabrication to generate the mask layers employed in the photolithography procedures.

• Design Rule Check: To ensure that the layout can be manufactured with minimal fabrication errors, the physical layout must follow the design guidelines the VLSI engineer set forth. 

During the production stage, they serve as an interface or communication channel between the process engineer and the circuit designer. Therefore, a DRC will be performed to ensure the plan complies with all design guidelines.

• LVS: Finally, the Layout Vs Schematic (LVS) equivalency checking will ensure that the design's functionality  is not altered during the physical design implementation layout. If there are additional device terminals, missing device terminals, or mismatched devices and nets in the layout or schematic, this equivalency will reveal them.

The final GDS-II file will be submitted to the foundry, where the actual silicon chips are fabricated using a silicon wafer following the completion of this implementation phase, which comprises the steps mentioned above.

Major VLSI Applications 

VLSI circuits are used in virtually every device today, including mobile phones, embedded processors, anti-lock brake systems in automobiles, personal entertainment systems, electronic medical systems, and personal computers.

VLSI technology is perfectly adapted to meet the needs of today's electronic devices and systems. Due to the growing desire for smaller, more compact, functional, and dependable devices, VLSI technology is predicted to continue to be the driving force behind improvements in electronics.

The number of job openings in the VLSI design field is also anticipated to increase as India develops its electronics system design and production skills, making it a viable career path for many.

List of VLSI Job Profiles You May Apply for After the Course 

Job prospects are immense; you must stack your portfolio with projects apart from securing VLSI certification. An entry-level VLSI expert in India gets a salary of up to ₹475,000. Here are a few of the career options after successful course completion.

• Physical Design Engineer: Designing the layout of a chip's digital and analogue circuitry will be one of their responsibilities as a layout engineer. Oscillators, references, ADCs, DACs, PLLs, and power management modules are a few examples.
• ASIC Verification Engineer: These professionals are in charge of the physical design of intricate digital circuits like ASICs and SoCs or sub-blocks as physical design engineers.
• Test Engineer: As an ASIC verification engineer, one must verify IPs and RTL code subblocks utilised in ASIC or SoC design.
• RF Engineer: Working on designs will involve testing them for general performance, speed, and noise. They are responsible for ensuring that each design complies with the requirements and standards.
• Embedded System Software Trainer: The curriculum for embedded system software is mainly focused on imparting theory and practical instruction in the C programming language, data structures, Linux programming, microcontrollers, embedded systems, network protocols, kernel fundamentals, and device drivers.

Conclusion 

The PGP covers the fundamental engineering facets of creating and implementing Integrated Circuits-based systems in Technology in VLSI Design and Embedded Systems. 

It concentrates on the abilities needed for the architecture of semiconductor devices and circuits with embedded components like CPU, Memory, and Peripherals. It incorporates both the dimensions of Material Science and Electrical Engineering.

Since 2015, Skill-Lync has provided advanced engineering course in VLSI for engineering students that apply to the industry by collaborating with industry leaders. Please call our experts today to receive 100% career-focused education.