Edram-Based Tiered-Reliability Memory With Applications To Low-Power Frame Buffers

Embedded DRAM (eDRAM) is becoming more and more popular as a low-cost alternative to on-chip SRAM. eDRAM is particularly attractive for frame buffers in video applications with ever increasing screen resolutions. However, eDRAM suffers short retention time and high refresh power, which prevents its widespread adoption. To save the refresh power of eDRAM-based frame buffers, we propose Tiered Reliability Memory (TRM), where the frame buffer is divided into multiple segments with different refresh periods and hence different error rates. By allocating most-significant bits to the most reliable segment, our four-tier TRM reduces refresh power by 48% without degrading user experience.