A distributed interleaving scheme for efficient access to WideIO DRAM memory

Abstract

Achieving the main memory (DRAM) required bandwidth at acceptable power levels for current and future applications is a major challenge for System-on-Chip designers for mobile platforms. Three dimensional (3D) integration and 3D stacked DRAM memories promise to provide a significant boost in bandwidth at low power levels by exploiting multiple channels and wide data interfaces. In this paper, we address the problem of efficiently exploiting the multiple channels provided by standard (JEDEC's WIDE-IO) 3D-stacked memories, to extract maximal effective bandwidth and minimize latency for main memory access. We propose a new distributed interleaved access method that leverages the on-chip interconnect to simplify the design and implementation of the DRAM controller, without impacting performance compared to traditional centralized implementations. We perform experiments on realistic workload for a mobile communication and multimedia platform and show that our proposed distributed interleaving memory access method improves the overall throughput while minimally impacting the performance of latency sensitive communication flows.