Research and Realization of Optimized Memory Access Scheduling Based on Rules

Memory Wall is a bottleneck of enhancing the performance of computer system. How to reduce Memory Access Latency is a problem that we have to deal with. In order to enhance the bandwidth and reduce the latency, MAS optimization utilizes the characters of DRAM to reschedule the memory access. In this paper, we make deep research on MAS (memory access scheduling) algorithm of DDR2 Memory Access Controller, the problem of MAS is NP-complete problem. Considering particular analysis the characters of DDR2, time relations of access operation and the cost of hardware, we propose a MAS algorithm based on rule. By studying effective data bar which is generated by Genetic Algorithm, we mine four rules. So we just use these four rules to schedule in Memory Access Controller. The results of experiment show that compared with FR-FCFS (first-ready first-come first-serve) scheduling strategy, the rule based algorithm improves the performance of scheduling and is near 1.5 times faster.