PDXML: extensible markup language for processor description

Abstract

This paper introduces PD-XML, a meta-language for describing instruction processors in general and with an emphasis on embedded processors, with the specific aim of enabling their rapid prototyping, evaluation and eventual design and implementation. The proposed methodology is based on the extensible markup language XML widely used structured information exchange and collaboration. PDXML allows for both high-level and low-level architectural specifications required to support a toolchain for design space exploration. PD-XML consists of three intuitive entities, describing: (a) the storage components available in a design, (b) the instructions supported by an architecture, and (c) the resources afforded by the microarchitecture implementation. PD-XML is not specific to any one architecture, compiler or simulation environment and hence provides greater flexibility than related machine description methodologies. We demonstrate how PD-XML can be interfaced to to existing description methodologies and tool-flows. In particular, we show how PD-XML specifications can be translated into appropriate machine descriptions for the parametric HPL-PD VLIW processor and for the flexible instruction processor approach.