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RASSP Methodology Application Note

1.0 Executive Summary

Figure 1 - 1: RASSP Design Process

Each major cycle of the spiral process represents an iteration of a virtual prototype. Within each prototype iteration, pieces of the design can and most likely will be at different levels of maturity, as shown in Figure 4 - 1. Each piece of the design may be represented by a mini-spiral where the spiral cycles correspond to virtual prototypes of the piece. Consequently, for each major spiral cycle, there may be activity in the system, architecture, and detailed design processes.

The overall RASSP development process, shown in Figure 1 - 1, has four major elements:

• Project planning/Management - Project planning/management provides the first step of the process: Develop the technical plan, and form the PDT (product development team) and the overall management approach for the specific signal processor development.

• Design Process - The design process represents development of the signal processor design from requirements capture through release to manufacturing. Is has three major processes: Systems design, architecture design, and detailed design. This process takes customer requirements and results in a fully verified (functionality and performance) virtual prototype of the signal processor.

• Systems Design Process - This process captures customer requirements and converts these system-level needs into processing requirements (functional and performance). Functional and performance analyses are performed to properly decompose the system-level description. The system process has only a very preliminary notion of either hardware versus software functionality or processor implementation.

• Architecture Design Process - The architecture process transforms processing requirements into a candidate architecture of hardware and software elements. Architecture selection initiates the trade-offs between the different processor architecture alternatives. During this process, the system-level processing requirements are allocated to hardware and/or software functions. The hardware and software functions are verified with each other via 'co-verification" at all steps. The architecture verification process results in a detailed behavioral description of the processor hardware and the definition of the software required for each processor in the system. The intent is to verify all the code during this portion of the design, ensuring hardware/software interoperability early in the design process.

• Detailed Design - As with the prior processes, the design is completed and verified for both hardware and software via a set of detailed functional and performance simulations. When this process is complete, the design is established, resulting in a fully verified virtual prototype of the system.

  During the hardware portion of the detailed design process, behavioral specifications of the processor are transformed into detailed designs (RTL, and/or logic-level) through a combination of hardware partitioning, parts selection, and synthesis. Detailed designs are functionally verified using integrated simulators, and performance/timing is also verified to ensure proper performance. The process results in detailed hardware layouts and artwork, net lists, and test vectors that can then be seamlessly transitioned to manufacturing and test via format conversion of the data.

  Since most of the software developments are verified during the architecture design phase, they are limited at this point to generation of those elements that are target-specific. This includes configuration files, bootstrap and download code, target-specific test codes, etc. All the software is compiled and verified (to the extent possible) on the final virtual prototype prior to the detailed design review. Design release to manufacturing marks the end of the RASSP design process.

• Prototype Manufacturing, Integration and Test - The manufacturing, integration and test processes define for RASSP the interface of design engineering to the disciplines required to build and test signal processor prototypes. This means the interaction of manufacturing and test personnel throughout the design cycle to support concurrent engineering through the release of the virtual prototype to manufacturing. This process also supports subsequent testing of the manufactured design and hardware/software integration of the signal processor.

• Specialty Engineering ('illities, etc.) - Specialty engineering covers all the non-design engineering tasks required to successfully develop and field RASSP products. These include reliability, maintainability, parts, and EMI engineering (where applicable), as well as integrated logistic support engineering and services.

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