Rapid design and prototyping of DSP systems

The rapid prototyping of application-specific signal processors (RASSP) [1-3] program of the United States Department of Defense (ARPA and Tri-Services) targets a 4X improvement in the design, prototyping, manufacturing, and support processes (relative to current practice). Based on a current practice study (1993) [4], the prototyping time from system requirements definition to production and deployment, of multiboard signal processors, is between 37 and 73 months. Out of this time, 25-49 months are devoted to detailed hardware=software (HW=SW) design and integration (with 10-24 months devoted to the latter task of integration). With the utilization of a promising top-down hardware-less codesign methodology based on VHSIC hardware description language (VHDL) models of HW=SW components at multiple abstractions, reduction in design time has been shown especially in the area of HW=SW integration [5]. The authors describe a top-down design approach in VHDL starting with the capture of system requirements in an executable form and through successive stages of design refinement, ending with a detailed hardware design. This HW=SW codesign process is based on the RASSP program design methodology called virtual prototyping, wherein VHDL models are used throughout the design process to capture the necessary information to describe the design as it develops through successive refinement and review. Examples are presented to illustrate the information captured at each stage in the process. Links between stages are described to clarify the flow of information from requirements to hardware.