This book describes techniques for how to verify and debug VLSI designs when bugs are found after the chips are fabricated and used in the field. This is the first book to cover many aspects of post-silicon verification and debugging techniques that utilize high-level design information, such as design descriptions in C/C++. Using high-level analysis on the error traces generated by fabricated chips maximizes the efficiency of the verification and debugging techniques presented in this book. Experimental results are included for real applications of the techniques presented.

This book provides a comprehensive coverage of System-on-Chip (SoC) post-silicon validation and debug challenges and state-of-the-art solutions with contributions from SoC designers, academic researchers as well as SoC verification experts. The readers will get a clear understanding of the existing debug infrastructure and how they can be effectively utilized to verify and debug SoCs.

This book describes automated debugging approaches for the bugs and the faults which appear in different abstraction levels of a hardware system. The authors employ a transaction-based debug approach to systems at the transaction-level, asserting the correct relation of transactions. The automated debug approach for design bugs finds the potential fault candidates at RTL and gate-level of a circuit. Debug techniques for logic bugs and synchronization bugs are demonstrated, enabling readers to localize the most difficult bugs. Debug automation for electrical faults (delay faults)finds the potentially failing speedpaths in a circuit at gate-level. The various debug approaches described achieve high diagnosis accuracy and reduce the debugging time, shortening the IC development cycle and increasing the productivity of designers. Describes a unified framework for debug automation used at both pre-silicon and post-silicon stages; Provides approaches for debug automation of a hardware system at different levels of abstraction, i.e., chip, gate-level, RTL and transaction level; Includes techniques for debug automation of design bugs and electrical faults, as well as an infrastructure to debug NoC-based multiprocessor SoCs.

During post-silicon validation and debug, manufactured integrated circuits (ICs) are tested in actual system environments to detect and fix design flaws (bugs). Traditional pre-silicon verification is inadequate; as a result, many critical bugs are detected only after ICs are manufactured (i.e., during post-silicon validation and debug). However, post-silicon validation and debug is challenging because traditional techniques are ad hoc (e.g., insertion of various Design for Debug structures based on various heuristics), and the associated costs are rising faster than design costs. These challenges are further magnified by the slowdown of silicon CMOS scaling, as ICs incorporate tremendous complexity to meet increasing demands for improvements in performance and energy efficiency. Examples include the use of multiple processor cores, co-processors, hardware accelerators, uncore components (defined as components in an SoC that are neither the processor cores nor the co-processors / accelerators; examples of uncore components include cache controllers, memory controllers, and interconnection networks), and power management units. This dissertation presents the Quick Error Detection (QED) technique to overcome post-silicon validation and debug challenges. QED is essential because long error detection latency, the time elapsed between the occurrence of an error caused by a bug and its manifestation as an observable failure, severely limits the effectiveness of existing post-silicon validation and debug approaches. Experimental results collected using several state-of-the-art commercial hardware platforms, as well as results obtained from simulations of various bug scenarios that occurred in commercial multi-core System-on-Chips (SoCs), demonstrate the effectiveness and practicality of QED: 1. QED improves error detection latencies by up to 9 orders of magnitude, from billions of clock cycles to very few clock cycles (generally fewer than 1,000 clock cycles for most bug scenarios). 2. QED enables up to 4-fold improvement in bug coverage (i.e., QED detects bugs that may be missed by traditional post-silicon validation approaches). 3. Symbolic Quick Error Detection (Symbolic QED) localizes difficult logic bugs automatically in a few hours (less than 7 hours for most bug scenarios), without requiring any additional hardware. Localizing a bug involves identifying a bug trace (defined as a sequence of inputs, e.g., instructions, that activates and detects the bug) and identifying the hardware design block where the bug is (possibly) located. This was demonstrated for an open-source multi-core SoC consisting of 500 millions transistors. In contrast, it might take days or weeks (or even months) of manual work, per bug, when traditional techniques are used. QED is effective for bugs inside processor cores, co-processors / software-programmable accelerators (which are components in an SoC that can be programmed using software to perform a specific set of functions, examples include graphic processing unit and digital signal processor), non-programmable hardware accelerators (which are components in a SoC that are designed to perform a pre-defined set of functions, but cannot be programmed using software, examples include accelerators for video or audio compression), and uncore components such as cache controllers, memory controllers, and interconnection networks. QED has been successfully used in industry during post-silicon validation and debug of a commercial multi-core SoC.

This book first provides a comprehensive coverage of state-of-the-art validation solutions based on real-time signal tracing to guarantee the correctness of VLSI circuits. The authors discuss several key challenges in post-silicon validation and provide automated solutions that are systematic and cost-effective. A series of automatic tracing solutions and innovative design for debug (DfD) techniques are described, including techniques for trace signal selection for enhancing visibility of functional errors, a multiplexed signal tracing strategy for improving functional error detection, a tracing solution for debugging electrical errors, an interconnection fabric for increasing data bandwidth and supporting multi-core debug, an interconnection fabric design and optimization technique to increase transfer flexibility and a DfD design and associated tracing solution for improving debug efficiency and expanding tracing window. The solutions presented in this book improve the validation quality of VLSI circuits, and ultimately enable the design and fabrication of reliable electronic devices.

This book provides comprehensive coverage of verification and debugging techniques for embedded software, which is frequently used in safety critical applications (e.g., automotive), where failures are unacceptable. Since the verification of complex systems needs to encompass the verification of both hardware and embedded software modules, this book focuses on verification and debugging approaches for embedded software with hardware dependencies. Coverage includes the entire flow of design, verification and debugging of embedded software and all key approaches to debugging, dynamic, static, and hybrid verification. This book discusses the current, industrial embedded software verification flow, as well as emerging trends with focus on formal and hybrid verification and debugging approaches.