In this paper, a novel multi-target design methodology based on the concepts of transformational design, and its application to the interlaced-to-progressive scan conversion (IPSC) problem, are discussed. Starting from a single high-level behavioral specification in VHDL a direction detector used in IPSC adgorithms is mapped onto both a custom implementation and a programmable video signall processor. Results are compared with those previously obtained using different tools and methodologies. 3.4.1 IEEE 1995 CUSTOM INTEGRATED CIRCUITS C0NFE:RENCE ' SIL was developed in cooperation with Philips Research and IMEC as part of the ESPRITBPRITE project 2260.

This paper discusses a novel transformation based design methodology and its use in the design of complex programmable VLSI systems. During the life cycl'e of a complex system the optimal trade-off between, partially, implementing in hardware or sofnvare is changing. This is due to varying system requirements (short time-tomarket, low-cost, low-power etc.) and improving device technology. The proposed methodology allows such redesigns to be made, using different hardware-software trade-offs, in a guaranteed correct way.

In this article we provide a practical transformational approach to the synthesis of correct synchronous digital hardware designs from high-level specifications. We do this while taking into account the complete life cycle of a design from early prototype to full custom implementation. Besides time-to-market, both flexibility with respect to target architecture and efficiency issues are addressed by the methodology. The utilization of user-selected behaviorpreserving transformation steps ensures first-time-right designs while exploiting the experience, flexibility, and creativity of the designer.To ensure that design transformations are indeed behavior-preserving a novel mechanized approach to the specification and verification of design transformations on control data flow graphs which is independent of a specific behavioral model or graph size has been developed.As a demonstration of an industrial application we use a video processing algorithm needed for the conversion from a line-interlaced to progressively scanned video format. Both a video signal processor-based prototype implementation as well as a very efficient full custom implementation are developed starting from a single high-level behavioral specification of the algorithm in VHDL. Results are compared with those previously obtained using different tools and methodologies.