ADL-driven Methodologies for Design Automation of Embedded Processors

This chapter describes various architecture description language (ADL)-driven methodologies for the development of efficient and reliable embedded processors. The ADLs are used to specify processor and memory architectures and generate software toolkits including the compiler, simulator, assembler, profiler, and debugger. The application programs are compiled and simulated, and the feedback is used to modify the ADL specification with the aim of finding the best possible architecture for a given set of application programs under various design constraints such as area, power, and performance, thus enabling performance-driven exploration. The simulator produces profiling data and thus may answer questions concerning the instruction set, the performance of an algorithm, and the required size of memory and registers. A promising approach to automatic compiler generation is the retargetable compiler approach. A compiler is classified as retargetable if it can be adapted to generate code for different target processors with significant reuse of the compiler source code. Retargetability is typically achieved by providing target machine information (in an ADL) as input to the compiler along with the program corresponding to the application. The ADL specification is also used to generate hardware models as well as functional test patterns to enable top-down validation of embedded processors. Thus the ADL-driven methodologies reduce time-to-market and enable generation of cost-effective and reliable embedded systems.