Pre- and Post-Fabrication Architecture Exploration for Partially Reconfigurable VLIW Processors

Modern application specific instruction-set processors (ASIPs) face the demanding task of delivering high performance for a wide range of applications. For enhancing the performance, architectural features e.g. pipelining, VLIW etc are often employed in ASIPs, leading to high design complexity. Integrated ASIP design environments like templated-based approaches [1] and language- driven approaches [2][3] provide an answer to this growing design complexity. At the same time, increasing hardware design costs have motivated the processor designers to introduce high flexibility in the processor. Flexibility, in its most effective form, can be introduced to the ASIP by coupling a re-configurable unit to the base processor. Due to its obvious benefits, several re-configurable ASIPs (rASIPs) have been designed in the recent years. These rASIP designs lacked a generic flow from high-level specification, resulting into intuitive design decisions and hard-to-retarget processor design tools. Although a template-based approach for rASIP design is existent, a clear design methodology especially for the pre-fabrication architecture exploration is not present. In order to address this issue, a high-level specification and design methodology for partially re-configurable VLIW processors is proposed in this paper. To show the benefit of this approach a commercial VLIW processor is used as the base architecture and two domains of applications are studied for potential performance gain.