Introduction to the special issue on application-specific processors

Abstract

Introduction to the Special Issue on Application-Specific Processors Application-specific processors offer performance, energy, and cost benefits compared to their general-purpose counterparts for a wide variety of market segments, ranging from low-cost micro-controllers to high-end supercomputers. The design and usage of application-specific processors are strikingly different from general-purpose comput- ers as the architecture is tuned to accelerate only a specific application or a class of applications. Application-specific architectures are often derived from a high-level specification of an application through a hardware/software co-design process, which can be highly automated; such a process would be inappropriate for general-purpose processor de- sign. Moreover, code compilation targeting application-specific processors is often inter- twined with the co-design process. Lastly, the system software may provide reduced and targeted functionality and interfaces at a much lower cost than a traditional embedded or real-time operating system such as iOS or Android. Historically, application-specific processors have been part of low-cost embedded devices; however, the landscape is rapidly changing. One important factor is the emer- gence of graphics processing units (GPUs) as general-purpose high-performance computing devices, which utilize graphics-specific hardware, but can also provide sig- nificant acceleration boosts for vectorizable applications. Similarly, reconfigurable computing devices, such as FPGAs, provide a flexible hardware fabric that can be used to implement a wide variety of application-specific functionality and as such are increasingly used for code acceleration in different domains. This special issue of ACM Transactions on Embedded Computing Systems is dedi- cated to all aspects of application-specific processors. Part of this special issue presents extended versions of some of the best papers that were presented at the IEEE Sym- posium on Application-Specific Processors (SASP) in 2009 and 2010. Altogether, we received 66 submitted manuscripts for the special issue, 10 of which were accepted for inclusion in this special issue. It is our great honor to introduce the articles. Our first article, “Hardware Architectural Support for Control Systems and Sensor Processing” by Sundhanshu Vyas, Adwait Gupta, Christopher Gill, Ron K. Cytron, Joseph Zambreno and Philip Jones, describes a microcontroller that has been cus- tomized to control thousands of PID controllers concurrently. Most application-specific processors in the past have extended RISCs or VLIWs. This article represents a land- mark effort in the design of customizable application-specific microcontrollers. This special issue features three articles that focus on the architecture of application- specific processors and the design of application-specific accelerators, namely, “Multicore-Based Vector Coprocessor Sharing for Performance and Energy Gains” by Spiridon F. Beldianu and Sotirios G. Ziavras, “A Systematic Approach for Optimized By- pass Configurations for Application-Specific Embedded Processors” by Thorsten Junge- blut, Boris Hubener, Mario Porrmann, and Ulrich R uckert, and “Custom Architecture for Multicore Audio Beamforming Systems” by Dimitris Theodoropoulos and Georgi Kuzmanov. They all represent interesting design points for different application- specific architectural styles. This is a large design space, and these three articles provide excellent insights about how one can customize a hardware platform. c 2013 ACM 1539-9087/2013/09-ART15 $15.00 DOI: http://dx.doi.org/10.1145/2514641.2514642 ACM Transactions on Embedded Computing Systems, Vol. 13, No. 2, Article 15, Publication date: September 2013.