LISA-machine description language and generic machine model for HW/SW co-design

A machine description language is presented. The language, LISA, and its generic machine model are able to produce bit- and cycle/phase-accurate processor models covering the specific needs of HW/SW codesign, and cosimulation environments. The development of a new language was necessary in order to cover the gap between coarse ISA models used in compilers, and instruction set simulators on the one hand, and detailed models used for hardware design on the other. The main part of the paper is devoted to behavioral pipeline modeling. The pipeline controller of the generic machine model is represented as an ASAP (as soon as possible) sequencer parameterized by precedence and resource constraints of operations of each instruction. The standard pipeline description based on reservation tables and Gantt charts was extended by additional operation descriptors which enable the detection of data and control hazards, and permit modeling of pipeline flushes. Using the newly introduced L-charts we reduced the parameterization of the pipeline controller to a minimum and at the same time covered typical pipeline controls found in state of the art signal processors. As an example, the application of the LISA model on the TI-TMS320C54x signal processor is presented