CAJ | 학술논문

DMA启动时间是评估DMA设计优劣的重要指标之一。在多核系统中，由于DMA需要响应的同步触发事件相对单核中DMA有大量的增加而影响到DMA的启动时间。在查询DMA同步事件时采用传统的令牌环方式不仅消耗的启动时间长而且还有很大的随机性。为了优化DMA的启动时间，在DMA查询同步事件时，文中采用轮转仲裁的方式实现了单周期查询到同步触发事件。此外，在设计结构上通过设置旁路的方式避免了逻辑通道写入事件队列的过程，最终使得DMA启动时间降低到5周期，相对采用传统DMA的启动速度有了较大提高。文中介绍了DMA启动设计实现方法，深入分析了影响DMA启动时间的主要因素，详细说明了令牌环和轮转仲裁的实现原理以及旁路的选择判断条件。
DMA계동시간시평고DMA설계우렬적중요지표지일。재다핵계통중，유우DMA수요향응적동보촉발사건상대단핵중DMA유대량적증가이영향도DMA적계동시간。재사순DMA동보사건시채용전통적령패배방식불부소모적계동시간장이차환유흔대적수궤성。위료우화DMA적계동시간，재DMA사순동보사건시，문중채용륜전중재적방식실현료단주기사순도동보촉발사건。차외，재설계결구상통과설치방로적방식피면료라집통도사입사건대렬적과정，최종사득DMA계동시간강저도5주기，상대채용전통DMA적계동속도유료교대제고。문중개소료DMA계동설계실현방법，심입분석료영향DMA계동시간적주요인소，상세설명료령패배화륜전중재적실현원리이급방로적선택판단조건。
The DMA startup time is one of the important indexes for evaluating the performance of the DMA design. Number of synchro-nization events of DMA in multi-core system has huge increase compared with DMA in single-core system to influence DMA startup time. In the query of DMA synchronization events,using the traditional token ring approach not only consumes long start-up time but al-so possesses much randomness. In order to reduce the startup time of DMA,introduce a round robin arbiter method which querying syn-chronization events only need 1 cycle. Besides,in the design of DMA startup,bypass is set so as to eliminate the process of logic channel writing into event queues,ultimately the start-up time of DMA is reduced to five cycle,compared with the traditional DMA,startup speed is greatly improved. In this paper,describe a DMA start design method,highly analyzing the main factors affecting the DMA startup time, elaborating the realization of the token ring and round robin arbiter used to query synchronization events,and analyzing the condition of choosing the bypass.