【作者】 曾伟；

【导师】 欧阳星明；

【作者基本信息】 华中科技大学 ， 计算机应用技术， 2008， 硕士

【摘要】 随着信息技术的发展,作为传统实验教学的一种有效补充,虚拟实验教学已成为加强实践教学、提高教学质量的重要手段。目前虚拟实验室的构建通常采用基于虚拟器件的方法,但这种方法在对逻辑功能不确定器件进行仿真时存在着器件功能模型无法建立的问题。将电路模拟技术引入虚拟教学实验系统,能够有效地解决可编程逻辑器件这类功能可定制器件的仿真。在深入分析虚拟实验教学系统的组织形式与结构以及传统实验环境下可编程逻辑器件的开发流程之后,根据可编程逻辑器件实验的特点,给出了基于电路模拟技术的可编程逻辑器件仿真方法。该方法采用对用户设计的电路进行建模,然后通过模拟电路的执行方式达到对可编程逻辑器件仿真的目的。电路建模包含两个方面,一是分析ABEL所描述电路的一般结构并设计出保存电路模型信息的文件格式,二是实现对ABEL语言的语义分析,从而达到从ABEL源文件获得电路模型信息的目的。在电路的模拟执行中,实际电路的并行运行效果是通过相应调度算法的控制来达到的。在此基础上,设计了一种改进的事件驱动模拟算法,并在模拟电路执行调度模块中进行了实现。此外,完成了模拟过程中数据结构以及外部接口的设计,实现了对ABEL电路中各种语句的模拟和模拟结果的波形显示。通过两个典型的应用实例对可编程逻辑器件仿真系统进行测试,结果表明,该系统达到了预期的设计要求。研究成果较好地解决了对逻辑功能不确定器件的仿真,并为虚拟教学实验室的研究提供了一个新的视角,具有良好的发展前景。更多还原

【Abstract】 Along with the development of information technology, as an effective complement of traditional experiment for teaching, virtual experiment has become the important means of enhancing practice and improving the quality of teaching. The construction of virtual laboratory usually based on virtual apparatus model at present. But there is a problem about construction of function model when using this method to simulate the device with uncertain logic function. The method based on circuit simulation technology can solve this problem effectively.After in-depth analysis of the forms of organization and structure of virtual laboratory and the development process of Programmable Logic Device (PLD) in traditional environment, a simulation strategy of PLD is put forward considering the feature of PLD experiment. This way of simulation modeling the circuit designed by user first, and then simulates the parallel operation of circuit, so as to archive the aim of simulation of PLD. Construction of the model of circuit has two aspects: firstly, analyze architecture of the circuit which is described by Advanced Boolean Expression Language (ABEL), then design format of the file which is used to save the model information of circuit; secondly, extract circuit model information from ABEL source file through the implementation of semantic analysis about ABEL. Simulate the operation of circuit means archive the effect of parallel operation of actual circuit under the control of scheduling algorithm. To archive this goal, the event-driven simulation algorithm is adopted and modified to suit for the simulation system, and it is implemented in the scheduling module of simulation system. Beyond that, the data structure which is used in scheduling module and interface that communicate with external system are designed, also the simulation of kinds of syntax of ABEL and waveform display about the simulate result are accomplished.The PLD simulation system is implemented and tested with two typical and practical examples. The result indicates that the system meets the expected design demand. The research achievement not only solves the simulation of device with uncertain logic function effectively, but also provides a new perspective for the research of virtual teaching laboratory.更多还原