Dvd Movement Control System, Embedded Real-time Kernel

A real-time multitasking kernel (also called real-time operating system, RTOS) is the foundation and development platform of embedded application software. A RTOS is software that manages the time of a microcontroller to ensure that all time critical activities are processed as quickly and efficiently as possible. A large number of complicated real-time applications can benefit from the use of a RTOS that generally simplifies the design process and allows the applications to be easily expanded and maintained. So far, a RTOS has been applied in a wide range of fields such as computers, communications, consumer electronics and more.Panasonic G5 DVD digital servo mechanism (i.e. DU5) is a typical embedded application that involves real-time information handling and real-time servo control. The original real-time kernel embedded in DU5 distinguishes itself from a commercial RTOS not only in compact TCBs (task control block) and flexible schedulers but also in supporting event flags management, which make it particularly well suited for an embedded control system.In this thesis, a thorough research into the original real-time kernel embedded in DU5 is performed in the following three steps:First, the architecture of hardware and software of DU5 is respectively illustrated. Moreover, the main features of the kernel built in DU5 are inferred from careful analysis on the typical software structure of a task based on the kernel.Next, a real-time system is discoursed on its characteristics, types and primary concepts. The comparison between a non-preemptive kernel and a preemptive kernel is discussed at length, especially in light of the process of scheduling.At last, several function units of the microcontroller used in DU5 are expatiated on the architecture and programming models relevant to the operation of the kernel. Furthermore, internals of the kernel is completely anatomized in terms of TCBs, scheduling, intertask communication and synchronization, etc. In addition, some potential faults in theory are detected and a preliminary correction is presented.