TESTING OF MICROPROCESSORS

With the growing use of the microprocessors the problematics of testing become more and more important for the reliability of the instrumentation. The paper gives a survey of the usual strategies and methods for CPU testing in microprocessor controlled equipment. The effects of the state-of-the-art field service methods on the self-test technology are discussed. Description of a new algorithm based on information compression is given together with some related realization experiences

Fault diagnostic instrumentation design for environmental control and life support systems

As a development phase moves toward flight hardware, the system availability becomes an important design aspect which requires high reliability and maintainability. As part of continous development efforts, a program to evaluate, design, and demonstrate advanced instrumentation fault diagnostics was successfully completed. Fault tolerance designs for reliability and other instrumenation capabilities to increase maintainability were evaluated and studied

Autonomous Recovery Of Reconfigurable Logic Devices Using Priority Escalation Of Slack

Field Programmable Gate Array (FPGA) devices offer a suitable platform for survivable hardware architectures in mission-critical systems. In this dissertation, active dynamic redundancy-based fault-handling techniques are proposed which exploit the dynamic partial reconfiguration capability of SRAM-based FPGAs. Self-adaptation is realized by employing reconfiguration in detection, diagnosis, and recovery phases. To extend these concepts to semiconductor aging and process variation in the deep submicron era, resilient adaptable processing systems are sought to maintain quality and throughput requirements despite the vulnerabilities of the underlying computational devices. A new approach to autonomous fault-handling which addresses these goals is developed using only a uniplex hardware arrangement. It operates by observing a health metric to achieve Fault Demotion using Recon- figurable Slack (FaDReS). Here an autonomous fault isolation scheme is employed which neither requires test vectors nor suspends the computational throughput, but instead observes the value of a health metric based on runtime input. The deterministic flow of the fault isolation scheme guarantees success in a bounded number of reconfigurations of the FPGA fabric. FaDReS is then extended to the Priority Using Resource Escalation (PURE) online redundancy scheme which considers fault-isolation latency and throughput trade-offs under a dynamic spare arrangement. While deep-submicron designs introduce new challenges, use of adaptive techniques are seen to provide several promising avenues for improving resilience. The scheme developed is demonstrated by hardware design of various signal processing circuits and their implementation on a Xilinx Virtex-4 FPGA device. These include a Discrete Cosine Transform (DCT) core, Motion Estimation (ME) engine, Finite Impulse Response (FIR) Filter, Support Vector Machine (SVM), and Advanced Encryption Standard (AES) blocks in addition to MCNC benchmark circuits. A iii significant reduction in power consumption is achieved ranging from 83% for low motion-activity scenes to 12.5% for high motion activity video scenes in a novel ME engine configuration. For a typical benchmark video sequence, PURE is shown to maintain a PSNR baseline near 32dB. The diagnosability, reconfiguration latency, and resource overhead of each approach is analyzed. Compared to previous alternatives, PURE maintains a PSNR within a difference of 4.02dB to 6.67dB from the fault-free baseline by escalating healthy resources to higher-priority signal processing functions. The results indicate the benefits of priority-aware resiliency over conventional redundancy approaches in terms of fault-recovery, power consumption, and resource-area requirements. Together, these provide a broad range of strategies to achieve autonomous recovery of reconfigurable logic devices under a variety of constraints, operating conditions, and optimization criteria

An Efficient Implementation of Built in Self Diagnosis for Low Power Test Pattern Generator

A New architecture of Built-In Self-Diagnosis is presented in this project. The logic Built-In-Self-Test architecture method is extreme response compaction architecture. This architecture first time enables an autonomous on-chip evaluation of test responses with negligible hardware overhead. Architecture advantage is all data, which is relevant for a subsequent diagnosis, is gathered during just one test session. Due to some reasons, the existing method Built-In Self-Test is less often applied to random logic than to embedded memories.  The generation of deterministic test patterns can become prohibitively high due to hardware overhead. The diagnostic resolution of compacted test responses is in many cases poor and the overhead required for an acceptable resolution may become too high.  Modifications in Linear Feedback Shift Register to generate test pattern with security for modified Built-In-Self-Test applications with reduced power requirement. The modified Built-In-Self-Test circuit incorporates a fault syndrome compression scheme and improves the circuit speed with reduction of time

Fault-tolerant building-block computer study

Ultra-reliable core computers are required for improving the reliability of complex military systems. Such computers can provide reliable fault diagnosis, failure circumvention, and, in some cases serve as an automated repairman for their host systems. A small set of building-block circuits which can be implemented as single very large integration devices, and which can be used with off-the-shelf microprocessors and memories to build self checking computer modules (SCCM) is described. Each SCCM is a microcomputer which is capable of detecting its own faults during normal operation and is described to communicate with other identical modules over one or more Mil Standard 1553A buses. Several SCCMs can be connected into a network with backup spares to provide fault-tolerant operation, i.e. automated recovery from faults. Alternative fault-tolerant SCCM configurations are discussed along with the cost and reliability associated with their implementation

The medical aspects of personal injury assessment

The doctor who writes the report on injury cases should be a specialist in this very specific field of medico-legal science, with considerable experience. In this article the author describes how such a doctor assesses and reports an injured individual.peer-reviewe

Long-term Results and Treatment Injuries in Pediatric Tibial and Femoral Fractures

Every fourth injured child seeking medical aid has sustained a fracture. Tibial fracture (annual incidence in less than 17 year old citizens in Finland is 1/1000) is the third most common fracture in children and femoral fracture (0.3/1000) among the most common pediatric injuries leading to hospitalization. Long-term treatment result of these fractures is not well known and there are no studies of treatment injuries in this pediatric patient population. Altogether 94 tibial and 74 femoral fractures were treated under anesthesia in Aurora Hospital, Helsinki between 1980-89. All but 5 of the tibial fractures were manipulated under anesthesia and casted. A remanipulation was performed in 41 patients. Femoral fractures were treated with skeletal traction in 62 patients, with internal fixation in 8 patients and by cast-immobilization 4 patients. A patients assessment form and an invitation to participate in a clinical and radiological examination at a mean follow-up of more than 20 years (16-32) was sent to all 168 patients. Six of the 58 tibial fracture patients that responded reported pain as their only memory of treatment. Results of tibial fracture treatment were satisfactory with few exceptions: functionally significant axial malalignment, limb length discrepancies nor arthritis was not found excluding four patients with >20° rotational deformity of the tibia. On the contrary 21/52 of the femoral fracture patients examined had angular malalignment of the femur exceeding 10°. Ten patients walked with a limp and leg-length discrepancy of more than 15 mm was measured in 8 patients. Knee arthritis had developed in 6/15 patients who were older than 10 years at the time of the injury. There was a positive correlation between angular deformity and knee arthritis. Treatment injuries were evaluated using patient compensation data from the Finnish Patient Insurance Centre (PIC): 50 claims involving tibial fracture treatment, 30 involving femoral fracture treatment were filed during the study period between 1997-2004. Compensation was granted in 35/50 claims after tibial fracture treatment and in 16/30 after femoral fracture treatment. The most common reasons for compensations in tibial fractures were missed diagnosis and inappropriate casting technique and delay in treatment, unnecessary or inappropriate treatment in femoral fractures. Most of the treatment injuries were regarded in retrospect as avoidable. Satisfactory long-term results in pediatric tibial fractures treated with closed manipulation and cast-immobilization can be expected. Many children require remanipulation to maintain satisfactory alignment, however. Over 10 year old patients with femoral malunion run a high risk of early knee arthritis. Most treatment injuries in pediatric tibial and femoral fractures can be avoided by accurate primary diagnostics, correct casting techniques and appropriate surgery.Lasten ja nuorten tapaturmista noin neljännes on murtumia. Säärimurtuma on lasten kolmanneksi yleisin murtuma (ilmaantuvuus Suomessa 1/1000) ja reisimurtuma (0.3/1000) yksi yleisimmistä sairaalahoitoon johtavista vammoista. Näiden vammojen hoitoon liittyvistä henkilövahingoista tai pitkäaikaishoitotuloksista on vähän tutkimustietoa. Auroran sairaalassa hoidettiin vuosina 1980-89 94 sääri- ja 74 reisimurtumaa, jotka vaativat nukutuksessa suoritetun toimenpiteen. Säärimurtumat hoidettiin viittä lukuun ottamatta ilman leikkausta, mutta lähes puolella potilaista murtuman asentoa jouduttiin myöhemmin korjaamaan kipsissä. Reisimurtumista 62 hoidettiin luuvedolla, 8 leikkaushoidolla ja 4 kipsihoidolla. Potilaille lähetettiin kyselykaavake hoidosta ja kutsu lääkärintarkastukseen sekä röntgenkuvaukseen. Kuusi kyselyyn vastanneista (n=58) ilmoitti kivun ainoana muistonaan säärimurtuman vuoksi saamastaan hoidosta. Hoitotulokset olivat lähes poikkeuksetta hyvät: merkittäviä virheasentoja, alaraajojen pituuseroa tai nivelrikkomuutoksia ei todettu lukuun ottamatta neljää potilasta, joilla oli yli 20° säären kiertovirhe. Sen sijaan lähes puolella 52:sta lääkärintarkastukseen osallistuneista reisimurtumapotilaista oli merkittävä reiden virheasento tai raajojen pituusero ja joka kymmenennellä oli polven nivelrikko. Kasvuikäisten kaikki 50 sääri- ja 30 reisimurtuman hoitoon liittyvää potilasvahinkoilmoitusta vuosilta 1997-2004 analysoitiin. Väärä diagnoosi ja puutteellinen kipsaustekniikka aiheuttivat valtaosan säärimurtumiin liittyvistä potilasvahingoista (n=35). Reisimurtumissa yleisimmät potilasvahinkoon (n=16) johtavat hoitovirheet olivat hoitoviive, tarpeeton tai epäasianmukaisesti toteutettu hoito. Valtaosa potilasvahingoista olisi voitu jälkikäteen arvioituna välttää. Tämän tutkimuksen perusteella kasvuikäisen säärimurtuman hoito voidaan toteuttaa luotettavasti ilman leikkausta. Yli kymmenen vuotiaan potilaan virheasentoon luutunut reisimurtuma on merkittävä riski polven nivelrikon kehittymiselle. Suurin osa potilasvahingoista lasten sääri- ja reisimurtumien hoidossa voidaan välttää huolellisella primaaridiagnostiikalla sekä kipsaus- ja leikkaustekniikalla

Fault Detection with Optimum March Test Algorithm

This paper presents a research work aimed to detect previously-undetected faults, either Write Disturb Faults (WDFs) or Deceptive Read Destructive Faults (DRDFs) or both in March Algorithm such as MATS++(6N), March C-(10N), March SR(14N), and March CL(12N). The main focus of this research is to improve fault coverage on Single Cell Faults as well as Static Double Cell Faults detection, using specified test algorithm. Transition Coupling Faults (CFtrs), Write Destructive Coupling Faults (CFwds) and Deceptive Read Destructive Faults (CFdrds) are types of faults mainly used in this research. The experiment result published in [1] shows BIST (Built-In-Self-Test) implementation with the new algorithm. It provides the same test length but with bigger area overhead, we therefore proposed a new 14N March Test Algorithm with fault coverage of more than 95% using solid 0s and 1s Data Background (DB). This paper reveals the design methodology to generate DB covers all memories function by applying non-transition data, transition data, and single read and double read data. The automation hardware was designed to give the flexibility to the user to generate other new March Algorithm prior to the selected algorithm and analyzed the performance in terms of fault detection and power consumption