Towards a Declarative Framework for Hardware-Software Codesign

We present an experimental framework for mapping declarative programs, written in a language known as Ruby, into various combinations of hardware and software. Strategies for parametrised partitioning into hardware and software can be captured concisely in this framework, and their validity can be checked using algebraic reasoning. The method has been used to guide the development of prototype compilers capable of producing, from a Ruby expression, a variety of implementations involving fieldprogrammable gate arrays (FPGAs) and microprocessors. The viability of this approach is illustrated using a number of examples for two reconfigurable systems, one containing an array of Algotronix devices and a PC host, and the other containing a transputer and a Xilinx device. 1 Introduction Although it has been known for many years that, from a functional point of view, there is little distinction between hardware and software, in current practice they are mostly developed using very different m..