机顶盒Sopca应用软件模块的设计实现

DESIGH AND IMPLEMENTATION OF STB SOPCA'S SOFEWARE MODULES

有限的硬件资源和实时性要求决定了嵌入式多媒体终端系统软件设计的复杂度 .我们设计并实现了一个称为Sopca的多媒体终端机顶盒的软件系统以支持数字电视的接收 .在 Sopca软件模块设计中 ,我们提出了一种基于任务的调度方法与策略 ,将各独立功能模块封装为以任务单元的形式存在 ,整个 Sopca功能的实现也是由各任务单元协调完成的 ,该策略强化了系统模块化、可移植和可扩展的要求 ,对嵌入领域中多媒体终端软件的设计是有推广意义的 .

The hardware resource limit and real time need have made it difficult to design multimedia terminal's software. We have designed and implemented a device's software system. This device is a set-top box called sopca that can receive and play digital TV programs. In designing sopca'ssoftware modules, we bring forward a scheduling method based on 13 tasks. One self _governed function is implemented in one task. And all sopca's functions are implemented via these task cells' coordination. This method boosts up system's modularity, scalability and transplantability. It has some significance for other embedded systems' design.