Estimates of execution time of embedded software play an important role in function-architecture co-design. This paper describes a technique based upon a statistical approach that improves existing estimation techniques. Our approach provides a degree of reliability in the error of the estimated execution time. We illustrate the technique using both control-oriented and computational-dominated benchmark programs.

An experimental set of tools that generate instruction set simulators,assemblers, and disassemblers from a single description wasdeveloped to test if retargetable development tools would work forcommercial DSP processors and microprocessors. The processorinstruction set was described using a language called nML. TheTMS320C50 DSP processor and the ARM7 microprocessor weremodeled in nML. The resulting instruction set models executeabout 25,000 instructions per second, and compiled instruction setsimulation models execute about 150,000 instructions per second.The viability of this approach and the deficiencies of nML are discussed.

System-level design requires some sort of specification for a system at the level of abstraction of the system. When the system (or sub-system) is a processor, the appropriate level of abstraction is the instruction set. However, there are no good approaches for describing processors at this level. Nevertheless, this type of specification has a number of benefits: it is more concise (and thus less error-prone) than more general alternatives; it can be re-used in later re-implementations; and it provides support for software codesign through compiler-generators (which rely on higher-level abstractions than other techniques provide). Therefore, we have developed a methodology and an embodying language for specifying processors at the instruction set level.>