A run-time word-level reconfigurable coarse-grain functional unit for a VLIW processor

Abstract

Nowadays, new DSP applications are offering combined and flexible multimedia and telecom services. VLIW processor architectures, which include dedicated but inflexible functional units, are usually tuned to a single specific application. In order to accelerate a wide range of applications, we propose a VLIW processor containing a novel run-time reconfigurable functional unit (RC-FU). Only a few hundred bits and few cycles are necessary to configure a new coarse-grain operation on the RC-FU unit. After reconfiguring its internal datapath and microprogram, the RC-FU can execute a number of look-alike DSP functions, such as 8-point DCT or 4-point FFT. The RC-FU itself is a VLIW processor and the configuration contexts are generated using a high-level synthesis tool. The proposed RC-FU provides high processing power and can be efficiently tuned to the requirements of a variety of DSP applications.