Implementation of verification methodologies

The increasing complexity of design elevates the importance of verification. This report explores different verification methodologies. The second chapter emphasizes the importance of testability and establishes the synthesis and DFT insertion flow using an SoC with ARM-Amber core as an example. Also, formal equivalence check is performed between the golden model, that is, RTL against its netlist. The third chapter delineates the design and formal verification of an Arbiter with APB slave configuration port. The design is extensively verified by writing SystemVerilog properties and we learn that the verification is only as good as the properties. Fourth chapter further explores formal verification with a different approach. The implemented x86 execution unit is formally verified by developing the its reference model and writing simple equality assertion checks. This approach exploits both, completeness of formal as well as includes the UVM reference model which reduces the long list of properties required for formal. The last chapter provides an approach to identify the critical registers in design. The critical flops in the design as a subset of all the registers which may have the most effect on the control flow of a module. This finds application in selecting the relevant auto-generated properties.Electrical and Computer Engineerin

On the Determinism of Multi-core Processors

Hard real time systems are evolving in order to respond to the increasing demand in complex functionalities while taking advantage of newer hardware. Software development for safety critical systems has to comply with strict requirements that will facilitate the certification process. During this process, each part of the system is evaluated, requiring a certain level of assurance in order to provide confidence in the product. In particular there must be a level of confidence that the system behaves deterministically that may be based on functionality, resources and time. The success of system verification depends greatly on the capacity to determine its exact behavior. Nonetheless, hardware evolved in order to maximize the average computation power throughput with little to no regard to the deterministic aspect. Therefore modern architectural features of processors, like pipelines, cache memories and co-processors, make it hard to verify that all the needed properties are respected. The multi-core is furthermore difficult to analyze as the architecture employs mechanisms that compromise strong spatial and temporal partitioning when using shared resources without rigorous access control like shared caches or shared input/outputs. In this paper we identify and analyze the main sources of nondeterminism of the multi-cores with regard to the timing estimation. Precise determination of the worst case execution time is a challenging task even in single-core architectures. The problems are accentuated in the multi-core context mainly due to the resource sharing that can lead to highly complex interactions or to nondeterminism. Most of the units that generate behaviors that are hard to take into account can be deactivated, but it is not always easy to predict the impact on the performance. Nevertheless some of the features cannot be disabled (such as the out of order execution or some nondeterministic crossbar access policies) which leads to the invalidation of the respective platform for applications with high criticality level. We will address the problematic units, propose configuration or architecture guidelines and estimate their impact on the performance and determinism of the system

Some recent asynchronous system design methodologies

Journal ArticleWe present an in-depth study of some techniques for asynchronous system design, analysis, and verification. After defining basic terminology, we take one simple example - a four-phase t o two-phase converter - and present its design using (a) classical flow-tables; (b) Signal Transition Graphs of [8]; and (c) Trace Theory of [15]. We then present necessary and sufficient conditions for Delay Insensitivity, proposed by [38], and illustrate it on our example. Finally, we present the work of [13] on the verification of asynchronous circuits, and illustrate it on the circuits derived in the paper. The following points are emphasized: (i) presentation of techniques at more depth than in a general survey; (ii) illustration of all t h e aspects discussed on a common example; (hi) comparative study of the works presented. Many interesting works had to be left out, solely because of our lack of space and time

Interpretation of clinical imagingexaminations by radiographers:a programme of research

Background Studies which have investigated the interpretation of plain skeletal examinations by radiographers have demonstrated encouraging findings, however, the studies have not extended beyond this area of practice and radiographers' diagnostic performance for other more complex investigations has not been established. Comparisons of performance between groups of healthcare practitioners to date, has also been limited. Aim This research programme aimed to investigate the interpretation of clinical imaging examinations by radiographers, and other healthcare practitioners, in the provision of initial interpretations and/or definitive reports of plain imaging ( skeletal and chest) and crosssectional (magnetic resonance imaging [MRI] – lumbar/thoracic spine, knees and internal auditory meati [IAM]) investigations. Methods The eight studies utilised a variety of methodological approaches and included quasiexperimental and observational studies. One quasi-experimental study compared the performance of radiographers, nurses and junior doctors in initial image interpretation and another similar study included a training intervention; both utilised alternate free-response receiver operating characteristic curve (AFROC) methodology. Three of the observational studies investigated the ability of radiographers to provide definitive reports on a wide range of clinical examinations, including chest and MRI investigations, in a controlled environment. One large multi-centre observational study investigated the performance of radiographers, in clinical practice (A/E: skeletal examinations) during the implementation of a radiographic reporting service. The agreement between consultant radiologists' MRI reports of lumbar/thoracic spine, knee and IAM examinations was investigated in another observational study. The final study compared the reports of trained radiographers and consultant radiologists, with those of an index radiologist, when reporting on MRI examinations of the knee and lumbar spine, as part of a prospective pre-implementation agreement study. Results The first AFROC study demonstrated statistically significant improvements after training, for radiographers (A1=0.55 - 0.72) and nurses (A1=0.65 - 0.63), although the radiographers maintained a better overall performance post training (p=0.004) in providing an initial image interpretation of trauma radiographs of the appendicular skeleton. Radiographers also achieved statistically higher (p<0.01) AUC values (A1=0.75) than nurses (A1=0.58) and junior doctors (A1=0.54) in the second AFROC study. Three studies, which examined 11155 reports, were conducted under controlled conditions in an academic setting and provided evidence of radiographers’ high levels of accuracy in reporting of skeletal A/E (93.9%); skeletal non A/E (92.5%); chest (89.0%); MRI lumbar/thoracic spine (87.2%), knees (86.3%) and IAM (98.4%) examinations. In the multi-centre clinical study, the mean accuracy, sensitivity and specificity rates of the radiographers reports (n=7179) of plain examinations of the skeletal system in the trauma setting was found to be 99%, 98% and 99%, respectively. The considerable range of values for agreement, between consultant radiologists reports of MRI examinations of the thoracic/lumbar spine (k=0 – 0.8), knee (k=0.3 – 0.8) and IAM (k=1.0) was similar to other studies and resulted in a reasonable estimation of the performance, in the UK, of an average non specialist consultant radiologist in MRI reporting. In the final study, radiographers reported in clinical practice conditions, on a prospective random sample of knee and lumbar spine MRI examinations, to a level of agreement comparable with non-musculoskeletal consultant radiologists (Mean difference in observer agreement <1%, p=0.86). Less than 10% of observers' reports (radiographers and consultant radiologists) were found to be sufficiently discordant to be clinically important. Conclusion The outcomes of this research programme demonstrate that radiographers can provide initial interpretations of radiographic examinations of the appendicular skeleton, in the trauma setting, to a higher level of accuracy than A/E practitioners. The findings also provide evidence that selected radiographers with appropriate education and training can provide definitive reports on plain clinical examinations (A/E and non A/E referral sources) of the skeletal system and the chest; and MRI examinations of the knee, lumbar/thoracic spine and IAM to a level of performance comparable to the average non specialist consultant radiologist. Wider implementation of radiographer reporting is therefore indicated and future multi-centre research, including economic evaluations, to further inform practice at a national level, is recommended

hArtes: Hardware-Software Codesign for Heterogeneous Multicore Platforms

Developing heterogeneous multicore platforms requires choosing the best hardware configuration for mapping the application, and modifying that application so that different parts execute on the most appropriate hardware component. The hArtes toolchain provides the option of automatic or semi-automatic support for this mapping. During test and validation on several computation-intensive applications, hArtes achieved substantial speedups and drastically reduced development times

HLS-lohkojen evaluointi ASIC-piirien toteutusvuossa

Digital systems continue growing in complexity, but the design and verification productivity has not been able to improve in the same manner, which has led to a productivity gap. Raising the abstraction level of the design with high-level synthesis (HLS) has been proposed to increase productivity. However, at the higher abstraction level, the designer has less control on the generated register-transfer level (RTL) code, which might cause problems later in the design flow. Moreover, certain design steps might be impractical to carry out with HLS. This thesis work investigates if HLS is compliant with an existing ASIC implementation flow. The research is conducted by creating an IP (intellectual property) block with a modern HLS tool and passing the generated RTL code through the various steps in the flow. The quality of results and design effort are also compared to the manually coded RTL implementation of the same IP. The HLS tool and the generated RTL code are found mostly compliant with the existing flow, but a few problems are identified in the ECOs (engineering change orders) and technology-specific component instantiation. The HLS design has almost equal physical area with the hand-written RTL design, and it meets the given timing constraints. Design effort with HLS is estimated 20-50% smaller compared to traditional RTL design, and the C++ code contains 60% fewer lines of code than the manually written VHDL code

Oh, Help Me in My Weakness : Entreaties and the Dissolution of Communal Time in John Wesley Harding

Using Walter Benjamin’s analysis of storytelling as a conceptual frame and referring to his ethical adherence to what Max Pensky termed Benjamin’s “melancholy dialectics,” this essay offers a thoroughgoing reading of Bob Dylan’s song “Drifter’s Escape” in order to examine the careful parsing of modes of public address and power Dylan undertakes in the song, and to argue that John Wesley Harding, as a song series, critiques dominant modes of American history telling. There has been a recent turn in Dylan Studies towards considering the songs as interventions in (or even works of) history. Taking this background as an essential turn in the field, especially considering the work the Bob Dylan Archive may enable, this essay argues that it is in temporal indeterminacy that Dylan’s work becomes&nbsp; a powerful expression of the vexations of history and memory in America. By “temporal indeterminacy” I mean to indicate a sense of the present shaped by an overflow of unprocessed (essentially silenced) memories and an almost pathological desire for the closure offered by dreams of historical redemption. Thereby the essay argues that the songs on John Wesley Harding are interventions in the typical modes of American storytelling rather than works of history themselves.Using Walter Benjamin’s analysis of storytelling as a conceptual frame and referring to his ethical adherence to what Max Pensky termed Benjamin’s “melancholy dialectics,” this essay offers a thoroughgoing reading of Bob Dylan’s song “Drifter’s Escape” in order to examine the careful parsing of modes of public address and power Dylan undertakes in the song, and to argue that John Wesley Harding, as a song series, critiques dominant modes of American history telling. There has been a recent turn in Dylan Studies towards considering the songs as interventions in (or even works of) history. Taking this background as an essential turn in the field, especially considering the work the Bob Dylan Archive may enable, this essay argues that it is in temporal indeterminacy that Dylan’s work becomes&nbsp; a powerful expression of the vexations of history and memory in America. By “temporal indeterminacy” I mean to indicate a sense of the present shaped by an overflow of unprocessed (essentially silenced) memories and an almost pathological desire for the closure offered by dreams of historical redemption. Thereby the essay argues that the songs on John Wesley Harding are interventions in the typical modes of American storytelling rather than works of history themselves