System Design for DSP Applications with the MASIC Methodology

University dissertation from Kista : Mikroelektronik och informationsteknik

Abstract: The difficulties of system design are persistentlyincreasing due to the integration of more functionality on asystem, time-to-market pressure, productivity gap, andperformance requirements. To address the system designproblems, design methodologies build system models at higherabstraction level. However, the design task to map an abstractfunctional model on a system architecture is nontrivial becausethe architecture contains a wide variety of system componentsand interconnection topology, and a given functionality can berealized in various ways depending on cost-performancetradeoffs. Therefore, a system design methodology must provideadequate design steps to map the abstract functionality on adetailed architecture.MASIC?Maths to ASIC?is a system design methodologytargeting DSP applications. In MASIC, we begin with afunctional model of the system. Next, the architecturaldecisions are captured to map the functionality on the systemarchitecture. We present a systematic approach to classify thearchitectural decisions in two categories: system leveldecisions (SLDs) and implementation level decisions (ILDs). Asa result of this categorization, we only need to consider asubset of the decisions at once. To capture these decisions inan abstract way, we present three transaction level models(TLMs) in the context of DSP systems. These TLMs capture thedesign decisions using abstract transactions where timing ismodeled only to describe the major synchronization events. As aresult the functionality can be mapped to the systemarchitecture without meticulous details. Also, the artifacts ofthe design decisions in terms of delay can be simulatedquickly. Thus the MASIC approach saves both modeling andsimulation time. It also facilitates the reuse of predesignedhardware and software components.To capture and inject the architectural decisionsefficiently, we present the grammar based language of MASIC.This language effectively helps us to implement the stepspertaining to the methodology. A Petri net based simulationtechnique is developed, which avoids the need to compile theMASIC description to VHDL for the sake of simulation. We alsopresent a divide and conquer based approach to verify the MASICmodel of a system.Keywords:System design methodology, Signal processingsystems, Design decision, Communication, Computation, Modeldevelopment, Transaction level model, System design language,Grammar, MASIC.