Asynchronous Core Research Articles

Design and Implementation of Asynchronous Processor on FPGA

Low-power and fault-tolerant features for microprocessors have been recognized as two of the greatest concerns in applications for edge devices. In this study, we propose asynchronous circuit design techniques for field-programmable gate arrays (FPGA) that can fundamentally overcome the drawbacks of conventional synchronous circuit designs. We used commercial FPGAs and implemented an asynchronous MSP430 microprocessor using the proposed technique. We also introduce an interfacing architecture between the synchronous block memory and asynchronous core to support the congeniality of the commercial embedded processor and the asynchronous core. Furthermore, we analyze a compiler for MSP430 and adapt its result to achieve a high-level development environment for asynchronous MSP430. The experimental results showed that the asynchronous MSP430 consumes 62.3% less power than its synchronous counterpart and has significant fault tolerance compared to the synchronous MSP430 under unstable supply voltage conditions. Additionally, the asynchronous MSP430 emitted 13% less electromagnetic noise at the working frequency.

Designing a High Enrollment Asynchronous Core Curriculum Science Course, General Animal Science for Declared Non-animal Science Majors

Abstract General Animal Science is a core curriculum science class providing students with an overview of the livestock industry. This case study describes delivery of a high enrollment (n = 634) asynchronous core curriculum science class, General Animal Science, for non-animal science majors. The class progresses from basic agriculture nomenclature, to reproduction, nutrition, genetics, food safety, and concludes with growth and development of beef, sheep, horses, swine, dairy, poultry, and provides a brief description of the companion animal industry. Asynchronous design requires clear and repetitive communication, organized course content, and effective faculty and student engagement. Use of multiple platforms including a learning management system (Canvas), email, and video announcements is helpful for communication and a detailed schedule creates expectations for course progression, vital in an asynchronous course. While content was delivered primarily via lecture and supplementary materials, optional zoom sessions and virtual office hours generate additional engagement opportunities. Learning outcomes were assessed via weekly topic-focused formative student activities and quizzes vs conventional summative exams. Automated grading of assessments provided students with frequent, real-time feedback. In a post-course survey conducted among students enrolled in the Fall 2020 course (n = 634), 97.9% of respondents agreed that course participation was a valuable learning experience and the majority (50.5%) attributed it to lectures, 22% to assignments, 12.2% to group projects, 11.04% to supplementary materials, and 3.9% to optional office hours. Respondents indicated a mean score of 2.02 (SD 2.84) on a Likert scale (0–10) on likely to change their major to Animal Science. This was expected as Biomedical sciences, Agribusiness, Economics, Psychology, and Business were the most frequently declared majors. We concluded that structured schedule utilizing multiple methods of communication and formative assessments are valuable components of a large asynchronous core curriculum general animal science course, and that this course has potential to educate and engage non-animal science majors.

Influencing Perceptions in Non-animal Science Majors: Impact of a High Enrollment, Asynchronous Core Curriculum Science General Animal Science Course

Abstract Perceptions of animal production industry and background knowledge of animal science vary greatly amongst students, particularly non-animal science majors. The objective was to assess the influence of a large asynchronous core curriculum science course, General Animal Science, on non-major student perceptions and knowledge of animal science. Student surveys (n = 634) were conducted (preceding and subsequent to course completion. The majority (57.66%) indicated no agriculture background. Among those reporting an agriculture background, 47.82% indicated having animal industry experience, and a mean score of 4.22 [SD 2.96; Likert scale (0–10)] evaluating perceived strength of their agriculture background. Of respondents, 34.77% indicated experience with companion animal, 13.6% beef cattle, 12.5% equine, 10.4% sheep and goats, 8.01% swine, 9.7% poultry, and 3.5% dairy cattle. Post-course responses were received from 71% of the enrolled students (n=541), and comprised of freshman (0–29 credit hours; n = 81), sophomore (30–59, n = 142), junior (60–89; n = 141), senior (90+; n = 48). Respondents indicated a mean score of 7.51 [SD 2.47; Likert scale (0–10)] that this course increased their interest in animal science and indicated a mean score of 6.71 (SD 2.97) on motivation to further their animal science knowledge. Students reported they felt more informed in beef cattle (40.10%), dairy cattle (15.05%), equine (14.56%), poultry (10.92%), swine (4.61%), and small animal (6.55%) production industries. Respondents (98.06%) indicated increased confidence as an educated consumer of animal products and a majority (92.2%) agreed this course helped eliminate misconceptions related to the animal production industry. In addition, 34.22% responded extremely likely, and 50.73% somewhat likely to utilize course knowledge in their everyday life. We concluded that enrollment in the asynchronous core curriculum science course, General Animal Science, reduced misconceptions related to animal production and increased knowledge of and appreciation of the animal production industry in non-animal science majors.

Spiral wave chimeras in reaction-diffusion systems: Phenomenon, mechanism and transitions

Spiral wave chimeras (SWCs), which combine the features of spiral waves and chimera states, are a new type of dynamical patterns emerged in spatiotemporal systems due to the spontaneous symmetry breaking of the system dynamics. In generating SWC, the conventional wisdom is that the dynamical elements should be coupled in a nonlocal fashion. For this reason, it is commonly believed that SWC is excluded from the general reaction-diffusion (RD) systems possessing only local couplings. Here, by an experimentally feasible model of a three-component FitzHugh–Nagumo-type RD system, we demonstrate that, even though the system elements are locally coupled, stable SWCs can still be observed in a wide region in the parameter space. The properties of SWCs are explored, and the underlying mechanisms are analyzed from the point view of coupled oscillators. Transitions from SWC to incoherent states are also investigated, and it is found that SWCs are typically destabilized in two scenarios, namely core breakup and core expansion. The former is characterized by a continuous breakup of the single asynchronous core into a number of small asynchronous cores, whereas the latter is featured by the continuous expansion of the single asynchronous core to the whole space. Remarkably, in the scenario of core expansion, the system may develop into an intriguing state in which regular spiral waves are embedded in a completely disordered background. This state, which is named shadowed spirals, manifests from a new perspective the coexistence of incoherent and coherent states in spatiotemporal systems, generalizing therefore the traditional concept of chimera states. Our studies provide an affirmative answer to the observation of SWCs in typical RD systems, and pave a way to the realization of SWCs in experiments.

Symmetry-breaking spirals

For a system to exhibit spiral patterns one would expect its parts to behave synchronously, as in a Mexican wave. Proving the contrary, chemical oscillators have now been observed in a state comprising a spiral surrounding an asynchronous core.

Scan Test Strategy for Asynchronous-Synchronous Interfaces

In the coming years, the well-known synchronous design style will not be able to keep pace with the increase speed and capabilities of integration of advanced processes. New design paradigms, like core reuse of the already designed synchronous modules and asynchronous designs, are considered in order to cope with the ever increasing complexity. The future SoCs will contain multiple synchronous and asynchronous cores. Asynchronous design will become more and more common among digital designers, while synchronous-asynchronous interactions will emerge as a key issue in the future SoC designs. This paper will present test strategies for 2-phase asynchronous-synchronous interfaces and vice versa. It will be shown how test vectors can be automatically generated using commercially available ATPG tools. The generated ATPG vectors will be able to test all stuck-at-faults within the asynchronous-synchronous interfaces.