International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

The once-ephemeral radiation-induced soft error has become a key threat to advanced commercial electronic components and systems. Left unchallenged, soft errors have the potential for inducing the highest failure rate of all other reliability mechanisms combined. This article briefly reviews the types of failure modes for soft errors, the three dominant radiation mechanisms responsible for creating soft errors in terrestrial applications, and how these soft errors are generated by the collection of radiation-induced charge. The soft error sensitivity as a function of technology scaling for various memory and logic components is then presented with a consideration of which applications are most likely to require soft error mitigation.

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Radiation-induced soft errors in advanced semiconductor technologies

A novel design technique is proposed for storage elements which are insensitive to radiation-induced single-event upsets. This technique is suitable for implementation in high density ASICs and static RAMs using submicron CMOS technology.

Upset hardened memory design for submicron CMOS technology

Physical mechanisms responsible for nondestructive single-event effects in digital microelectronics are reviewed, concentrating on silicon MOS devices and integrated circuits. A brief historical overview of single-event effects in space and terrestrial systems is given, and upset mechanisms in dynamic random access memories, static random access memories, and combinational logic are detailed. Techniques for mitigating single-event upset are described, as well as methods for predicting device and circuit single-event response using computer simulations. The impact of technology trends on single-event susceptibility and future areas of concern are explored.

Basic mechanisms and modeling of single-event upset in digital microelectronics

Single-event upsets from particle strikes have become a key challenge in microprocessor design. Techniques to deal with these transients faults exist, but come at a cost. Designers clearly require accurate estimates of processor error rates to make appropriate cost/reliability tradeoffs. This paper describes a method for generating these estimates. A key aspect of this analysis is that some single-bit faults (such as those occurring in the branch predictor) do not produce an error in a program's output. We define a structure's architectural vulnerability factor (AVF) as the probability that a fault in that particular structure do not result in an error. A structure's error rate is the product of its raw error rate, as determined by process and circuit technology, and the AVF. Unfortunately, computing AVFs of complex structures, such as the instruction queue, can be quite involved. We identify numerous cases, such as prefetches, dynamically dead code, and wrong-path instructions, in which a fault do not affect, correct execution. We instrument a detailed 1A64 processor simulator to map bit-level microarchitectural state to these cases, generating per-structure AVF estimates. This analysis shows AVFs of 28% and 9% for the instruction queue and execution units, respectively, averaged across dynamic sections of the entire CPU2000 benchmark suite.

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A systematic methodology to compute the architectural vulnerability factors for a high-performance microprocessor

Fault tolerant circuits are currently required in several major application sectors. Besides and in complement to other possible approaches such as proving or analytical modeling whose applicability and accuracy are significantly restricted in the case of complex fault tolerant systems, fault-injection has been recognized to be particularly attractive and valuable. Fault injection provides a method of assessing the dependability of a system under test. It involves inserting faults into a system and monitoring the system to determine its behavior in response to a fault. Several fault injection techniques have been proposed and practically experimented. They can be grouped into hardware-based fault injection, software-based fault injection, simulation-based fault injection, emulation-based fault injection and hybrid fault injection. This paper presents a survey on fault injection techniques with comparison of the different injection techniques and an overview on the different tools.

A Survey on Fault Injection Techniques

This paper investigates an approach to study the effects of upsets on the operation of microprocessor-based digital architectures. The method is based on the injection of bit-flips, randomly in time and location by using the capabilities of typical application boards. Experimental results, obtained on programs running on two different digital boards, built around an 80C51 microcontroller and a 320C50 Digital Signal Processor, illustrate the potentialities of this new strategy.

Predicting error rate for microprocessor-based digital architectures through C.E.U. (Code Emulating Upsets) injection

This volume provides an extensive overview of radiation effects on integrated circuits, offering major guidelines for coping with radiation effects on components. It contains a set of chapters based on the tutorials presented at the International School on Effects of Radiation on Embedded Systems for Space Applications (SERESSA) that was held in Manaus, Brazil, November 20-25, 2005.

Radiation Effects on Embedded Systems

This paper deals with a software modification strategy allowing on-line detection of transient errors. Being based on a set of rules for introducing redundancy in the high-level code, the method can be completely automated, and is therefore particularly suited for low-cost safety-critical microprocessor-based applications. Experimental results are presented and discussed, demonstrating the effectiveness of the approach in terms of fault detection capabilities.

Raoul Velazco

Papers

Upset hardened memory design for submicron CMOS technology

A Survey on Fault Injection Techniques

Predicting error rate for microprocessor-based digital architectures through C.E.U. (Code Emulating Upsets) injection

Radiation Effects on Embedded Systems

Experimentally evaluating an automatic approach for generating safety-critical software with respect to transient errors