A Two-Port SRAM for Real-Time Video Processor Saving 53% of Bitline Power with Majority Logic and Data-Bit Reordering

We propose a low-power two-port SRAM suitable for real-time video processing. In order to minimize discharge power on a read bitline, a majority-logic decides if input data are inverted in a write cycle, so that "1"s are in the majority. In video data, since more significant bits of adjacent pixel data are fortunately lopsided to either "0" or "1" with higher probability, the data bits in the pixels are reordered in each digit group to exploit the majority logic. The speed and area overheads are 4% and 11% in a 90-nm process technology, respectively. The proposed SRAM achieves 53% power reduction on the bitlines, and saves 43% of a total power when considered as an H.264 reconstructed-image memory.