Real-Time Control of I/O COTS Peripherals for Embedded Systems
Real-Time Control of I/O COTS Peripherals for Embedded Systems
复制标题
嵌入式系统 I/O COTS 外设的实时控制
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
L. Sha
中科院分区：
文献类型：
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作者：
Stanley Bak;E. Betti;R. Pellizzoni;M. Caccamo;L. Sha
实时嵌入式系统越来越多地使用商用现货（COTS）组件（如批量生产的外围设备和总线）来构建，以降低成本、缩短上市时间并提高性能。不幸的是，COTS互连系统通常不能保证及时性，并且在存在高带宽I/O外围设备的情况下可能会经历严重的时序退化。为了解决这个问题，我们设计了一个实时I/O管理系统，包括1）实时桥，2）预留控制器。该框架用于透明地将基于COTS的嵌入式系统的I/O子系统置于实时调度的约束下。我们还讨论了计算I/O数据事务的延迟范围和确定最坏情况下的缓冲区大小。最后，我们通过实验证明，我们的原型实时I/O管理系统成功地优先I/O流量，并保证其及时性。
Real-time embedded systems are increasingly being built using commercial-off-the-shelf (COTS) components such as mass-produced peripherals and buses to reduce costs, time-to-market, and increase performance. Unfortunately, COTS interconnect systems do not usually guarantee timeliness, and might experience severe timing degradation in the presence of high-bandwidth I/O peripherals. To address this problem, we designed a real-time I/O management system comprised of 1) real-time bridges, and 2) a reservation controller. The proposed framework is used to transparently put the I/O subsystem of a COTS-based embedded system under the discipline of real-time scheduling. We also discuss computing a delay bound for I/O data transactions and determining worst-case buffer size. Finally, we demonstrate experimentally that our prototype real-time I/O management system successfully prioritizes I/O traffic and guarantees its timeliness.