Understanding the Role of Verification and Validation in VLSI Product Development

Design verification is critical in VLSI product development as it ensures that the product or system meets the specified requirements, compliance, and standards. It involves checking the design at each stage of the development process to catch and rectify errors before the product goes into production. By prioritizing design verification, companies can minimize product defects, improve product quality, and ultimately enhance customer satisfaction.

Verification and testing account for almost 80% of the overall time spent in product development. Testing and verification are key focus for many foundries, and it is necessary at every stage of VLSI design. Mistakes in any phase require returning to the initial steps to fix them.

Verification and validation though often used interchangeably, are distinct processes with distinct objectives and approaches. To clarify the distinction, let's begin with the definitions as presented on Wikipedia (https://en.wikipedia.org/wiki/Verification_and_validation):

"Verification is intended to check that a product, service, or system (or portion thereof, or set thereof) meets a set of design specifications."

"Validation is intended to ensure a product, service, or system (or portion thereof, or set thereof) results in a product, service, or system (or portion thereof, or set thereof) that meets the operational needs of the user."

The distinction between verification and validation is primarily based on the testing context, as described in the above definitions. Verification involves testing the design's accuracy against its specifications, while validation involves testing the design's accuracy against the requirements of the intended user. Although the user's requirements should have informed the design specifications, this should be explicitly validated.

Approaches Used for VLSI Design Verification

In VLSI (Very Large Scale Integration) design, verification checks whether a design meets its intended functionality and specifications. There are several approaches for design verification in VLSI, including:

Simulation-Based Verification

This approach involves simulating the design using a software tool to ensure its correct functionality. Different types of simulation can be performed, such as functional, timing, and power.

Formal Verification

This mathematical approach verifies whether the design meets its specifications. Formal verification uses mathematical algorithms and tools to prove the correctness of the design.

Emulation-Based Verification

Designers use emulation to test the functionality of the design on a hardware platform. Emulation allows the design to be verified in a natural environment and is a common approach for complex designs that are difficult to simulate.

Static Verification

This method verifies the design before simulation or emulation is performed. Static verification tools analyze the design and check for syntax errors, design rule violations, and functional inconsistencies.

Post-Silicon Verification

This approach involves verifying the design after fabrication on a chip. Post-silicon verification involves testing the chip to ensure its functionality and identify defects.

Each approach has advantages and limitations, and designers often combine them to verify their designs thoroughly.

Some More Verification Methods in VLSI Design

VLSI design typically employs two types of verifications: functional verification and static timing analysis.

Functional verification tests whether the system or design behavior is active, while static timing analysis (STA) confirms that timing requirements are met. It would be best if you carried out both types of verification at every stage of the design process, including translation, placement, and routing.

Verification Phases in VLSI Design

In VLSI, verification occurs in two phases:

• First, predictive analysis is carried out to ensure that the synthesized design will perform the specified I/O function when built.
• Next, during the test phase, the actual gadget created from the synthesized design is subjected to product testing to verify no manufacturing defects.

The design verification process involves producing test outcomes that match the product requirements, specifications, and actual design outputs, which constitute a genuine product. Depending on the design being verified, a test case or test suite may be executed, an inspection may be conducted, or an analysis may be performed to provide the necessary evidence.

Wrapping Up

Design verification is crucial to VLSI product development, ensuring the product meets the required standards and specifications. Verification and testing are time-consuming processes, but they help companies minimize defects and improve product quality, ultimately leading to customer satisfaction.

Due to the intricacy of modern semiconductor digital designs, a multi-pronged strategy is required for the verification and validation process, covering crucial aspects of verification at every stage of silicon design. ACL Digital offers high-quality VLSI verification and validation services to ASIC/FPGA/SoC manufacturers, OEMs, and design houses serving various industries such as automotive, industrial automation, consumer electronics, networking, and more.Our VLSI experts employ cutting-edge technological tools, approaches, and languages to perform silicon verification and validation.

ACL Digital has extensive experience in verification and validation to help clients achieve their objectives of having first-pass quality silicon tape out or VLSI IPs in the market. Our team possesses hands-on experience with top verification tools that enable faster and more accurate results. The verification team can work on intricate SoCs, IPs, sub-systems, ASIC and FPGA-based designs, block-level verification, develop a robust verification test bench, and secure the environment.