System on Chip (SoC) is becoming more and more complex in terms of functional capabilities, computing power, multi-interface support and performance. SoC manufacturers strive to bring in as many features and capabilities as possible while scaling-down the Chip form-factor. This increasing complexity in chip design combined with faster time-to-market demands throw enormous challenges for Chip developers, which multiplies the efforts in SoC verification and validation. Verification, Validation and Testing are three important stages of Chip Development. It is crucial to have functional test platforms when the first pre-production sample of the SoC is out. Pre Silicon Validation [SoC Validation platform] is often considered as the most critical phase of Chip development. It validates various attributes of an SoC such as power sequencing, reset and clocking schemes including boot mechanisms, and the SoC functional correctness. Further to this, the SoC release also has dependencies on power and performance parameters, thermal and electrical parameters, physical stress tests in a given environment. The features and functionalities intended to be achieved by the Chip need to be thoroughly verified and validated. The silicon verification, validation and testing processes consume the same amount of time or sometimes even more of the total chip development time. SoC validation is performed under aggressive schedules to meet time-to-market requirements. And this is where Test Platform developers play a crucial role by providing fully functional and validated test platforms before the actual silicon is ready.

The Test Platform development team develops the SoC Validation platform parallel to the chip development activity and ensure that the platform is ready by the time first silicon [Sample SoC] is out. This blog aims at providing a glimpse of SoC validation platform development and the validation processes at various stages of Chip development.

Typical Chip Development Flow

A typical Chip development process includes stages viz., Design Spec, Architecture design, RTL Design, Physical Design, Tapeout and Manufacturing. The Chip design verification happens during the chip development process. It’s crucial to have a clear roadmap for Chip release and Test/Validation Platform development, as the timely market release of a new Chip is dependent on its Validation.

Fig: Typical Chip Manufacturing Flow

Silicon Validation Platform

Mostly SoC manufacturers deploy a different project team to work on Silicon Validation Platforms. Depending on the Chip Development Lifecycle and the complexity of the platform, Silicon Manufacturers may also employ an experienced Embedded design company to develop the Test Platform.

The figure below outlines various phases in the development of a Test Platform in cohesion with Chip Development activity.

Fig: Phases of Silicon Validation test platform development & Support

Pre-Silicon Phase

The SoC Validation Platform (SVP) design can start during the early stages of the SoC development itself. The Test Platform is designed in close coordination with the SoC design team. SVP developers seek various information on SoC such as the interfaces, SoC packaging, Power/Clock, end applications etc. from the SoC design team. This is to ensure that various features and functional capabilities envisioned in the SoC can be validated using the Validation platform.

Testing of Validation Platform

The complexity of the SVP increases with the complexity of the SoC. Hence, it is critical to validate the platform to ensure its robustness. The platform needs to be thoroughly tested to validate its functional correctness and performance before the actual SoC is available and debugged if any issues are noticed. This helps to minimize failures when the actual SoC is under test. There are several means to test a Validation platform.
Silicon Bring-up

A fully tested and functional Test Platform is used for Silicon bring-up activities. Typically, a Chip Manufacturer uses the actual fabricated silicon [Pre-production sample] to run the software and conduct the Silicon Validation Process. In this process, all functionalities and target use-cases of the chip are verified and validated. All major interfaces of SoC are functionally made available for verification on the platform. The process thoroughly analyses the performance of the SoC and tests the corners to validate the operating limits. The Test Platform development team is actively involved in the validation processes and supports the silicon team in setting up the system for checking out various boot modes and also the peripherals. The Test Platform development team also provides support in debugging failures if any are detected during the validation process.

Post silicon Phase

Silicon Validation is a continuous process and any functionality failures, bugs identified, or an upgrade required in the Test Platform is addressed in this phase. The Chip development team provides silicon samples to the platform developers to verify their findings. The Test Platform developers replicate these cases as applicable [Failures] and resolve the failure conditions.

The Chip Development team engages multiple line-ups to test various interfaces, peripherals, and functionalities at the same time. Test Platform Developers provide test suites and required documentation to ease out the initial setup and operation of the system. Once the Silicon/Chip is thoroughly validated with respect to all functional aspects, the chip Manufacturers team can proceed with the next phase of Silicon release.

Conclusion

Silicon validation is one of the crucial processes in chip release. It takes a palpable amount of time and effort to realize and implement a test architecture that meets all test requirements of a new SoC. In many instances, Chip Manufacturers depend on Product Engineering companies for the timely development of Silicon Validation Platforms. Mistral is an embedded engineering company having more than two decades of experience in collaborating with leading chip manufacturers in developing Test/Validation platforms, Evaluation Modules, Development Platforms and assisting them in successfully validating their SoCs. Mistral is one of the preferred design partners for Silicon companies. Mistral has in-depth knowledge on key components the validation processes that help chip manufacturers get their chips to market faster.

To know more about Silicon Validation and Test Platform Development Services, write to us info@mistralsolutions.com