A 50% Power Reduction in H.264/AVC HDTV Video Decoder LSI by Dynamic Voltage Scaling in Elastic Pipeline

We propose an elastic pipeline that can apply dynamic voltage scaling (DVS) to hardwired logic circuits. In order to demonstrate its feasibility, a hardwired H.264/AVC HDTV decoder is designed as a real-time application. An entropy decoding process is divided into context-based adaptive binary arithmetic coding (CABAC) and syntax element decoding (SED), which has advantages of smoothing workload for CABAC and keeping efficiency of the elastic pipeline. An operating frequency and supply voltage are dynamically modulated every slot depending on workload of H.264 decoding to minimize power. We optimize the number of slots per frame to enhance power reduction. The proposed decoder achieves a power reduction of 50% in a 90-nm process technology, compared to the conventional clock-gating scheme. key words: H.264/AVC, DVS (dynamic voltage scaling), elastic pipeline, low power, divided entropy decoder