面向共享资源冲突的SoC并发时钟调度管理

SoC Concurrent Clock Scheduling Management Oriented to Shared Resource Conflict

片上系统（SoC）的多任务并发性使得总线和主存等共享资源的竞争日趋频繁，如何在满足系统峰值功耗需求的同时减少资源冲突带来的功耗损失是系统级时钟管理的难点。为此，提出一种SoC系统级时钟调度管理方法，在不影响系统性能的前提下，根据各计算单元在共享资源上的竞争概率，计算各单元由于竞争冲突导致的等待时间，进而在已知任务截止时间的前提下，分析各个任务的实际有效工作时间，通过软件调配各计算单元时钟频率调度共享资源的访问，实现系统在满足峰值功率约束下的总功耗最优化。实验结果表明，该方法可降低3．3％～38．2％的SoC系统总功耗。

System on Chip（SoC） multi-task concurrency leads to more frequent competitions on shared resources like bus and main memory. How to reduce the power consumption caused by resource conflicts while meeting peak power requirements of the system has become a major challenge on system-level clock management. In this paper, a system-level SoC clock scheduling management method is proposed to achieve optimal total power consumption under the peak power constraint. Without any impact on system performance, it calculates the waiting time of each unit caused by resource conflicts according to their competition probabilities on shared resources, and further analyzes the effective working time of each task as the finishing time of tasks is known. The optimization target is then reached by using software to deploy the clock frequency of each unit to schedule shared resource access. Experimental results show that total power consumption can be reduced from 3.3% to 38.2% with this method.