Abstract: In order to reduce accessing delay of the shared main memory sub-system(MMS) of Zhong ke SoC, this paper analyzes the consistence of the timing delay by a behavior model of L*Bus. It reduces the average refuse rate and access delay of the MMS evidently by using the operation queue and the open-page memory controller in the MMS. It also presents a M/M/1/N queuing model for MMS, tests MMS and MMS_E system in the MMSITE , and the result shows that the key parameters of the MMS like accessing delay, total data read and write per second and read /write operation count per millisecond have been improved a lot after the optimization .

Key words: SoC, Memory accessing delay, Open-Page memory controller, Queuing model

摘要： 围绕降低中科SoC主设备访问共享内存子系统延迟的目标，从总线模型的角度分析了访存延迟的构成，通过在接口电路中设置操作队列以及在底层采用基于Open-Page的内存控制器等措施，降低了访存平均拒绝率，减少了访存的延迟；对主存子系统建立了M/M/1/N排队模型，用集成测试环境MMSITE分别对优化前后的子系统进行了测试。结果表明，访存延时、单位时间内读写数据总量以及单位时间内完成读写次数等主要性能指标都有较好的改善。

关键词: SoC, 访存延时, Open-Page 内存控制器, 排队模型