自己整理的一个关于如何使用modelsim进行功能仿真，时序仿真和布局布线的后仿真的文档，例子是抄的，针对的版本是modelsim se6.2b-Their finishing a feature on how to use modelsim for simulation, timing simulation and post-layout simulation of the document, copy the example is for the version of modelsim se