Today, we congratulate Yonghui Li on his first accepted journal article. The article is entitled “Architecture and Analysis of a Dynamically-Scheduled Real-Time Memory Controller” and has been accepted in the Real-Time Systems journal. The work extends his paper “Dynamic Command Scheduling for Real-Time Memory Controllers” that was presented at ECRTS 2014. The previous conference paper introduced a back-end architecture and scheduling algorithm for a dynamically scheduled SDRAM controller supporting variable transaction sizes and different degrees of bank interleaving. The properties of the back-end was extensively analyzed and worst-case execution times (WCET) of scheduled transactions was derived using two different methods with varying complexity and accuracy.
The newly accepted article extends this work by proposing a corresponding memory controller front-end, along with a complete response time analysis for memory transactions of variable sizes. A key feature of the front-end is that it features a non-work-conserving TDM arbiter, which provides static information about the order in which transactions of different sizes are scheduled, allowing the response time analysis to leverage the flexible WCET analysis of the back-end to provide tighter bounds. In addition, it is shown in which order memory clients with different request sizes should be served to minimize the total response time. The results demonstrate that dynamic command scheduling significantly outperforms our semi-static (pattern-based) approach in the average case, while it performs equally well or better in the worst-case with only a few exceptions.