This paper proposes a data encoder to reduce switched capacitance on system bus. Our method focuses on transferring raw video data (pixels) between off-chip memory and on-chip memory which is common in video compression applications. This method is based on entropy coding to minimize bus transition. The existing technique exploits the correlation between neighbouring pixels. In our technique, we exploit pixel correlation between two consecutive frames. Our method shows 54% transition saving when combined with the existing technique which is equivalent to 38% power saving for 15pF off-chip bus capacitance. This method is suitable for applications where multiple frames are transferred from off-chip memories such as in MPEG-4 AVC/H.264 encoder.
Asral Bahari, Tughrul Arslan, Ahmet T. Erdogan