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.