Quadratic zero-one programming-based synthesis of application-specific data paths

In this paper, a novel technique for the synthesis of complex multifunctional units is presented. Given a set of functions, the goal is to minimize the area cost of a unit that can execute these functions. A set of primitive functional units is allocated and shared between operations which belong to different functions. In the presented approach, a bipartite matching-based technique is extended with a quadratic cost function which allows for a much more accurate modeling of interconnect cost compared to previous approaches. In the optimization process, functional unit type selection, instance allocation, and instance assignment are performed simultaneously. As an extension of the technique, a set of constraints which exclude solutions with false combinatorial cycles are also presented. The technique finds its main applicability in the synthesis of custom accelerator data paths in high throughput signal processing applications, as required in video, image processing, front end speech processing, and user-end telecom. In addition, it can be applied in the synthesis of the data path of domain-specific instruction set processors. Experiments show that highly optimized results can be obtained within acceptable CPU times