用自顶向下法设计交通灯控制系统  

The Traffic Light Controlling System Design Using Top-down Method

作　　者：杨恒新[1] 

机构地区：[1]南京邮电大学光电工程学院,江苏南京210003

出　　处：《电气电子教学学报》2006年第4期39-41,86,共4页Journal of Electrical and Electronic Education

摘　　要：自顶向下法是数字系统设计通常采用的一种方法。一般教材在讨论交通灯系统设计举例时,因为没有给出完整的ASM图,导致定时电路模块的设计过程不清晰,实质上该部分的设计采用了传统的试凑法,而非自顶向下法。为便于完整地理解自顶向下设计方法,本文给出交通灯控制系统完整的ASM图,采用自顶向下方法设计定时电路,并与试凑法设计结果进行比较。为了验证设计的正确性,采用VHDL语言描述该交通灯系统,并给出MAX+plusⅡ输出的仿真结果,证实了设计的正确性。对数字系统设计的教学具有一定的参考价值。Top-down method is a generic digital system designing method, but usually it isn＇t given in schoolbooks that the full ASM map about a design example of the traffic light controlling system, so the results in fact that the designing process of the timing circuit module of this system isn＇t distinct. Actually, this module is designed based on bottom-up try and error method but not top-down method. In order to fathom the top-down designing method, it is given in this paper that the full ASM map about the traffic light controlling system, and the timing circuit module is designed based on top-down mothed and is compared with the circuit designed based on try and error method. For confirming the correcttness of the design, the final digital system is described with VHDL language, the MAX＋plus Ⅱ simulating result is brought out, and the result attests to the legitimacy of designed circuits. This paper takes on some referrence value for classroom teaching of the digital system.

关 键 词：数字系统 VHDL仿真 课堂教学 

分 类 号：TN79[电子电信—电路与系统] G642.4[文化科学—高等教育学]