Validation is acknowledged as a major bottleneck in systemonchip soc design methodology. Pdf bridging presilicon verification and postsilicon. Recent studies suggest that postsilicon validation consumes more than 50% of an socs overall design effort total cost at 65nm technology. The goal of validation is to deliver a bugfree product by exercising every cell of the. Postsilicon validation is widely acknowledged as a major bottleneck for complex integrated circuits ics including modern microprocessors as well as complex systemonchip soc designs. Trends in fpga testing and validation signal processing. New algorithms and architectures for postsilicon validation. A structured approach to postsilicon validation and debug using. There also exists a variety of testing solutions that combine. Postsilicon validation and debug prabhat mishra springer. Abstractapplying formal methods to assist in the post silicon debugging of complex digital designs presents challenges that are distinct from those found in pre silicon formal verification. It includes a large number of interrelated activities each with its own nuance and subtleties, requires extensive planning, and spans the entire system design lifecycle. I interviewed at apple san jose, ca us in april 2018.
Postsilicon validation is a complex and critical component of a modern systemonchip soc design verification. This phase also tries to check the functional correctness of the design but on the real hardware in the actual working environment. Efficient presilicon validation and postsilicon tuning. Postsilicon validation is used to detect and fix bugs in integrated circuits and systems after manufacture. The post silicon validation phase in a processors design life cycle is our last opportunity to find functional and electrical bugs in the design before shipping it to customers. To accelerate postsilicon validation, highquality tests. Postsilicon validation is an essential part of modern integrated circuit design to capture bugs and design errors that escape presilicon validation. Post silicon validation is a major bottleneck in soc design methodology. This presents a unique opportunity for aggressive checking. Even with very advanced pre silicon verification tools, post silicon validation psv is one of the most crucial steps in ensuring the functional correctness of the chip design. However, there is little data evaluating the coverage of post silicon validation efforts on industrialscale designs. Pdf post silicon validation is the final process in semiconductor chip manufacturing. The pressure of maintaining aggressive launch schedules and containing an increased cost of validation and debug, require a holistic approach to the entire design and validation process. Transformations for post silicon validation tests must not adversely degrade coverage.
Code coverage for postsilicon validation mehdi karimibiuki embedded linux conference 20 san francisco, ca 22 feb, 20. In post silicon debug, a set of observed events or conditions describes a. Pdf on jun 30, 2016, imran ahmed published pre and post silicon validation automation with graphics behavior checker find, read and. Postsilicon validation is a major bottleneck in soc design methodology. Functional validation fv is one among many methods used in post silicon validation. Post silicon validation psv of first silicon tends to be an ad hoc process, stitching together protocol testers from various manufacturers to create test cases and debug issues. Describes automated techniques for generating postsilicon tests and assertions to enable effective postsilicon debug and coverage analysis. This paper presents an automated approach for postsilicon debugging of design bugs by integrating post silicon trace analysis, modelbased diagnosis, and diagnostic trace generation. Due to sheer design complexity, it is nearly impossible to detect and fix all bugs before manufacture. To reduce manual effort being spent during postsilicon validation, automated. Postsilicon validation methodology in soc part 1 of 2.
She wines at her more beautiful sister with tales of loss of system performance or odd intermittent failures. Pdf pre and post silicon validation automation with graphics. Free interview details posted anonymously by intel corporation interview candidates. This demands innovative approaches to speeding up postsilicon validation and reducing its cost. These are often due to onchip asynchronous events and electrical effects. Coverage is the standard measure for validation effectiveness and is extensively used pre silicon. For the complex designs of today, traditional methods for psv will be very time consuming but these measures are unavoidable. Salary estimates are based on 2 salaries submitted anonymously to glassdoor by post silicon validation engineer employees.
Post silicon validation requires effective techniques to better evaluate the functional correctness of modern systemsonchip. Post silicon validation is not a new idea and has been used for many years in many places. A unified methodology for presilicon verification and. Postsilicon validation methodology in soc part 2 of 2. The post sil icon validation also known as blackbox testing has limited visibility in the design. In this work we present cosma, a novel technology offering high coverage functional post silicon validation of. Today, it is largely viewed as an art with very few systematic solutions. This merged test will be a master test that will provide considerable amount of saving in terms of. Design validation and debugging university of california. Critical design bugs escape pre silicon verification and are detected only during post silicon validation adir 11, friedler 14, foster 15, keshava 10, mitra 10. Two rounds of phone interviews, first one was a general overview with some technical questions, second was a coderpad quiz on python.
To identify design errors that escape pre silicon veri cation, post silicon validation is becoming an important step in the implementation ow of digital integrated circuits. Request pdf postsilicon validation and debug this book provides a comprehensive coverage of systemonchip soc postsilicon validation and debug challenges and stateoftheart solutions. Post silicon engineering silicon debug, characterization, etc is very important under large scale process variations compressed silicon sensing cs is a revolutionary theory lets take advantage of it at ic design and manufacturing. In postsilicon debug, a set of observed events or conditions describes a failure scenario. Electrical bug localization during postsilicon validation. Intel corporation post silicon validation engineer. Post silicon validation is a complex and critical component of a modern systemonchip soc design verification. Filter by location to see post silicon validation engineer salaries in your area.
Covers scalable postsilicon validation and bug localization using a combination of simulationbased techniques and formal methods. Pre silicon instrumentation and atspeed post silicon validation tools can enhance observability and control of internal signals. During post silicon validation, manufactured integrated circuits are extensively tested in actual system environments to detect design bugs. Postsilicon validation system for modern microprocessors. They employ onchip reconfigurable instruments that developers can insert and customize at design time for atspeed data acquisition, performance monitoring, stimulus, and fault injection functions, but are ultimately programmed post silicon, while the system is in.
Vcd pattern generation and conversion guidelines, test spectrum inc. Yerramilli, intel vp fab pre silicon verification inadequate. The national average salary for a post silicon validation engineer is. Postsilicon bug diagnosis with inconsistent executions. Post silicon validation is a vital phase of verification that deals with. Bug localization involves identification of a bug trace a sequence of inputs that activates and detects the bug and a hardware design block where the bug is located. When a design passes from presilicon verification, few initial prototypes of the chips are fabricated and are used as test objects. Unified coverage methodology for soc postsilicon validation. Prabhat mishra is a professor in the department of computer and information science and engineering at the university of florida.
It should be clarified that it is not necessary for postsilicon validation to completely diagnose or root cause a bug. Postsilicon debug using formal verification waypoints. Postsilicon validation, on the other hand, benefits from very high raw performance, since tests are executed directly on manufactured silicon. His research interests include embedded and cyberphysical systems, energyaware computing, hardware security and trust, systemonchip verification, bioinformatics, and postsilicon validation and debug. Postsilicon validation opportunities, challenges and. Postsilicon validation consumes an increasing share of the overall product development time 1. Coverage evaluation of postsilicon validation tests with. While ics are getting to market, the process is far from ideal.
Upon completion of each test, the output of the silicon. Efficient trace signal selection for post silicon validation and debug. At the same time, it poses several challenges to traditional validation methodologies, because of the limited internal observability and difficulty of applying modifications to manufactured silicon chips. Bridging presilicon verification and postsilicon validation. It accounts for an estimated 70 per cent of overall time and resources spent on soc design validation.
Despite innovation in design verification methodology, the gap between design and verification continues to be sizable, and the role of post silicon validation. Pre and postsilicon techniques to deal with largescale. The challenges of post silicon validation are continuously increasing, driven by higher levels of integration, increased circuit complexity, and platform performance requirements. Apply to validation engineer, senior hardware engineer, entry level engineer and more. In industry practice, the postsilicon validation process begins when the.
It is important to take the pre silicon methods and algorithms to post silicon validation. Atpg automatic test patter generation 11 with techniques for silicon state acquisition such as scan. Postsilicon code coverage for functional verification of. Postsilicon validation is deployed to capture the escaped bugs from the presilicon verification phase. In post silicon validation, test program inputs may be known a priori bentley 01.
Postsilicon validation is a major challenge for future systems. Efficient combination of trace and scan signals for post silicon. Presents case studies for postsilicon debug of industrial soc designs. A structured approach to postsilicon validation and debug.
Hence, debugging a failure in this environment is laborious and timeconsuming 1. Traditional pre silicon verification is inadequate for difficult logic bugs. She does not have the swish tools, beautiful methodologies and classy abstractions at her disposal like. Abstractapplying formal methods to assist in the postsilicon debugging of complex digital designs presents challenges that are distinct from those found in presilicon formal verification. The primary goal of postsilicon validation is to identify design errors by exploiting the speed of postsilicon execution. Bridging pre silicon verification and postsilicon validation. Validation domain characteristics pre silicon validation cycle accurate simulation f sim post silicon validation tests run at f prod. Postsilicon validation of the memory subsystem in multicore designs andrew deorio, ilya wagner and valeria bertacco university of michigan. These chips are then connected to specialized validation platforms that facilitate running postsilicon tests, a mix of directed and constrainedrandom workloads. Postsilicon validation is a major challenge due to finite controllability and observability of actual silicon and makes debug a complex task.