Zero-overhead loop controller for implementing multimedia algorithms

Multimedia algorithms in their majority consist of regular repetitive loop constructs. In this paper, a novel control unit design for implementing such loop intensive algorithms is described. The proposed architecture, termed as zero-overhead loop controller (ZOLC) exploits the regularity of computations, which is a common characteristic of multimedia algorithms in order to efficiently support the corresponding datapaths. The ZOLC controls the operations in datapath modules by activating/deactivating their corresponding controlling FSMs. Algorithmic flow dependencies, which determine the appropriate loop sequencing are mapped on a look-up table (LUT). For another algorithm to execute, LUT context and FSM configurations only have to be reprogrammed, assuming a generic datapath. Thus, partial reconfiguration possibilities for implementing multimedia algorithms on programmable platforms can be exploited. As proof-of-concept, implementations of algorithms of the multimedia domain are investigated to evaluate the performance of the proposed unit, against other methods of control. Also, a full-search motion estimation processor employing the ZOLC is synthesized. It is proven that the ZOLC provides flexibility by supporting various algorithms of the multimedia field with performance improvements up to 2.1 over conventional control methods.