一．课题要求：
仔细分析单片机操作系统RTX51的原理，将其移植到单片机实验平台上，并要求编写一个简短的程序来验证其运行的正确性（比如，编写两个具有显示不一样内容的任务）。
二．RTX51原理
注释：由于英文原文会比较好，所以我没有翻译过来（不过也写了部分的翻译），直接提取出来一些英文，总结在一起。
1. 进程管理( Task Management )
1) 进程类型( Classes of Tasks )
RTX-51 recognizes two classes of tasks:
1. Fast tasks
n Contain especially short responses and interrupt disable times.
n Contain a separate register bank and a separate stack area (register banks 1, 2 and 3).(Figure 1)
n Contain the highest task priority (priority 3) and can therefore interrupt standard tasks.
n All contain the same priority and can therefore not be mutually interrupted.
n Can be interrupted by c51 interrupt functions.
n A maximum of three fast tasks can be active in the system.
2. Standard tasks
n Require somewhat more time for the task switching compared to fast tasks.
n Share a common register bank and a common stack area (register bank 0).
n The current contents of registers and stack are stored in the external (XDATA) memory during a task change.
n Can be interrupted by fast tasks.
n Can interrupt themselves mutually.
n Can be interrupt by c51 interrupt functions.
n A maximum 16 standard tasks can be active in the system.
<单片机操作系统RTX51原理分析>
