A Priority-Based 6T/8T Hybrid SRAM Architecture for Aggressive Voltage Scaling in Video Applications

作者：Chang Ik Joon^*; Mohapatra Debabrata; Roy Kaushik

来源：IEEE Transactions on Circuits and Systems for Video Technology, 2011, 21(2): 101-112.

DOI：10.1109/TCSVT.2011.2105550

• Aggressive voltage scaling in SRAM
• hybrid SRAM array
• low power SRAM design
• process variation resilient SRAM
• video memory

We present a voltage-scalable and process-variation resilient, hybrid memory architecture, suitable for use in MPEG-4 video processors such that power dissipation can be traded for graceful degradation in "quality." The key innovation in our proposed work is a hybrid memory array, which is a mixture of conventional 6T and 8T SRAM bit-cells. The fundamental premise of our approach lies in the fact that the human visual system is mostly sensitive to higher order bits of luminance pixels in video data. We implemented a preferential storage policy in which the higher order luma bits are stored in robust 8T bit-cells while the lower order bits are stored in conventional 6T bit-cells. This facilitates aggressive scaling of supply voltage in memory as the important luma bits, stored in 8T bit-cells, remain relatively unaffected by voltage scaling. The not-so-important lower order luma bits, stored in 6T bit-cells, if affected, contribute insignificantly to the overall degradation in output video quality. Simulation results show that under iso-area condition, we can obtain at least 32% power savings in the hybrid memory array compared to the conventional 6T SRAM array.

• 出版日期2011-2