A novel approach for flexible and consistent ADL-driven ASIP design

Architecture description languages (ADL) have been established to aid the design of application-specific instruction-set processors (ASIP). Their main contribution is the automatic generation of a software toolkit, including C compiler, assembler, linker, and instruction-set simulator. Hence, the challenge in the design of such ADLs is to unambiguously capture the architectural information required for the toolkit generation in a single model. This is particularly difficult for C compiler and simulator, as both require information about the instructions' semantics, however, while the C compiler needs to know what an instructions does, the simulator needs to know how. Existing ADLs solve this problem by either introducing redundancy or by limiting the language's flexibility.This paper presents a novel, mixed-level approach for ADL-based instruction-set description, which offers maximum flexibility while preventing from inconsistencies. Moreover, it enables capturing instruction- and cycle-accurate descriptions in a single model. The feasibility and design efficiency of our approach is demonstrated with a number of contemporary, real-world processor architectures.