The data reading control module PI control module serial communication module variable-frequency control module and so on have been realized by using top-down design and down-top idea . The software implement and timing simulation figures are shown in this paper .

运用 自顶向下和自底向上的思想完成了数据读取控制、PI调节、串行通讯、变频等模块的设计，并给出了软件实现图及 仿真时序图。

Taking the crank slider mechanism as an example the product design process of top-down assembly design combined motion simulation based on SolidWorks platform was presented .

以曲柄滑块机构为例，介绍了在SolidWorks平台上 自顶向下装配体设计与运动 仿真相结合进行产品开发的过程。

Compared with the existing top-down models the proposed model focuses on the interactive rules between trains . The proposed model becomes a powerful tool for design simulation and analyses of coordinated train control .

相比已有的 自上而下建立的列车运行控制模型，本文提出的模型关注对列车间交互规则的描述，这为列车协同控制方法的设计、 仿真和分析提供了有力的工具。

On the basis of top-down assembly design method the assembly and simulation of the work attachment on a multi-function loader is performed by using framework model . The accuracy of assembly is ensured as well as the design efficiency is improved .

基于 自上而下的装配设计（Top-DownAssemblyDesign）方法，采用骨架模型完成了多用途装载机工作装置的装配与 运动 仿真，既保证了装配精度，又提高了设计效率。

The defects of conventional down-top assembly design were brought forward and the product design method of top-down assembly design combined motion simulation was proposed .

指出了传统的自底向上装配体设计的缺点，并提出 自顶向下装配体设计与运动 仿真相结合的产品设计方法。

The design of MCS-51 Microcontroller is followed the Top-Down design way including system partition coding ( VHDL ) RTL simulation synthesis gate level simulation ect .

对MCS&51单片机进行 正向设计，包括系统划分、编写代码、RTL级 仿真与综合、门级仿真等。