Implementing a streaming application on a processor array

A modern way of processing information is to do it in parallel. This Master Thesis conducts a case study of how to parallelize a streaming application on a highly parallel platform. This involves porting a real-world application, written in a stream processing language and compiled by tools, developed by the Embedded System Design research group at Lund University, onto a platform including an embedded processor array (the Adapteva’s Epiphany), an ARM processor, and programmable logic. The driver application that we used was a video decoder. The host platform was a Parallella board, with a 16-core Epiphany co-processor and a Zynq host processor that had dual ARM cores. Our Master Thesis covers the creation of some library elements to support complex applications on that platform, such as FIFOs between Epiphany cores and the ARM host, some components that handle access to external RAM and a component that draws pixels onto a screen.A modern way of processing information is to do it in parallel. This master’s thesis conducts a case study of how to parallelize an application on a highly parallel platform

High-level synthesis of dataflow programs for heterogeneous platforms:design flow tools and design space exploration

The growing complexity of digital signal processing applications implemented in programmable logic and embedded processors make a compelling case the use of high-level methodologies for their design and implementation. Past research has shown that for complex systems, raising the level of abstraction does not necessarily come at a cost in terms of performance or resource requirements. As a matter of fact, high-level synthesis tools supporting such a high abstraction often rival and on occasion improve low-level design. In spite of these successes, high-level synthesis still relies on programs being written with the target and often the synthesis process, in mind. In other words, imperative languages such as C or C++, most used languages for high-level synthesis, are either modified or a constrained subset is used to make parallelism explicit. In addition, a proper behavioral description that permits the unification for hardware and software design is still an elusive goal for heterogeneous platforms. A promising behavioral description capable of expressing both sequential and parallel application is RVC-CAL. RVC-CAL is a dataflow programming language that permits design abstraction, modularity, and portability. The objective of this thesis is to provide a high-level synthesis solution for RVC-CAL dataflow programs and provide an RVC-CAL design flow for heterogeneous platforms. The main contributions of this thesis are: a high-level synthesis infrastructure that supports the full specification of RVC-CAL, an action selection strategy for supporting parallel read and writes of list of tokens in hardware synthesis, a dynamic fine-grain profiling for synthesized dataflow programs, an iterative design space exploration framework that permits the performance estimation, analysis, and optimization of heterogeneous platforms, and finally a clock gating strategy that reduces the dynamic power consumption. Experimental results on all stages of the provided design flow, demonstrate the capabilities of the tools for high-level synthesis, software hardware Co-Design, design space exploration, and power optimization for reconfigurable hardware. Consequently, this work proves the viability of complex systems design and implementation using dataflow programming, not only for system-level simulation but real heterogeneous implementations

High-level Synthesis of Dataflow Programs for Signal Processing Systems

The growing complexity of signal processing algorithms and platforms poses significant challenges to design methods and implementation tools. High-level dataflow programs, such as those in MPEG's RVC-CAL language, provide abstraction and the opportunity for extensive design-space exploration, but they do raise the problem of efficient automatic synthesis to hardware and software. This paper presents a tool called Xronos that efficiently synthesizes RVC-CAL programs to an RTL-level hardware description and significantly improves on previous efforts in both quality of the resulting implementation and synthesis speed. By directly supporting all the features of the RVC-CAL language, it translates unmodified standard MPEG reference code to a functioning hardware implementation. The paper describes the essential processing architecture of Xronos, the differences from other related approaches and experimental results that show Xronos to produce faster and smaller implementations, while at the same time significantly reducing synthesis time