National Chiao-Tung University

Department of Electronics Engineering & Institute of Electronics

On-Demand Memory System for Wireless Video Entertainment Systems

Student : Yung Chang

Advisor : Dr. Wei Hwang


With increasing demands on ubiquitous wireless high-data-rate multimedia services, it is critical to have efficient processing capability and a merging multi-task system to sustain the growth. Therefore, a well-organized memory system can provide enough bandwidth and optimize memory managements. In this thesis, an on-demand memory system is presented to overcome the challenges in the multi-task and heterogeneous multi-core system design. The proposed on-demand memory system, consisting of distributed and centralized memory management units (MMUs), provides energy-efficient memory-centric on-chip data communication for wireless video entertainment systems.

Distributed MMUs (d-MMUs) can dynamically allocate the memory resource for network data buffering to reduce the stall of processor elements based on the proposed borrowing mechanism. Furthermore, the c-MMU manages centralized on-chip memories (L2 cache) and off-chip memories. For different memory requirement of the processor elements in the system, adaptive memory resource allocation is applied via the proposed adaptive cache control. Additionally, in order to access off-chip DRAM efficiently, an external memory interface is designed in c-MMU. By considering the characteristics of the wireless video data, an inter-layer pre-fetch mechanism and an efficient data allocation scheme are proposed to reduce the cache miss rate and memory energy consumptions for Scalable Video Coding (SVC).