Embedded Kernel And Peripheral Component Studying

According to the shortcoming that programmer lays particular stress on the single thread in traditional personal software design process, through studying several kinds of popular embedded systems at present, a simple miniature personal embedded system has been developed. The system has a simple kernel and some peripherally building blocks. Strive to transform traditional background software design process into multi-thread software design process through fewer efforts. The system includes the communication and dispatcher among the tasks, memory management, serial communication module, timing module, the keyboard module, etc.Task kernel adopts preemptive and dynamic priority. According to the phenomenon of deadlock and priority's overturn, propose better solution. According to the communication and synchronization of multiple tasks, three method have been put forward: disable interrupt and enable interrupt; locking and unlocking the scheduler; event control methods realizing with semaphore, message mail box and message queue. And to realizing the communication and synchronism among the tasks with semaphore, message mailbox and message queue has introduced the detailed one. Through dividing large successive memory blocks and using the same size of memory piece each time realize the functions of management of memory. That using the functions of management of memory can effectively avoid the memory chip question appearing in dynamic memory assigning.As to the design of outside modules, offer design thought, design block diagram, realization of serial communication module, timing module, the keyboard module, and discrete input/output module, etc. Thereby effectively realize function of embedded system kernel's input, outside communication and time management.Through setting some value of head file, can compile the code that designer wants to use.which can reduce the total code greatly. Thus make systematic kernel and some peripheries easy to cut out. Though these kinds of the cutting technologies of module, programmer can effective control his own code to his idea, reduce the repeated development cost of the system.Though the module design process analysis, one can very easy add and get rid of some procedures with target and environment changing constantly, but needn't revise the kernel part. So the system can be in pace with hour.