说明：  此文档为fpga控制双口RAM的开发文档，讲解很细，易于上手.双口RAM是在1个SRAM存储器上具有两套完全独立的数据线、地址线和读写控制线，并允许两个独立的系统同时对其进行随机性访问的存储器，即共享式多端口存储器。
(This document is controlled dual-port RAM fpga development documents, explain very small, easy to use. Dual-port RAM is an SRAM memory has two completely separate data lines, address lines and control lines to read and write, and allows two independent system while its random access memory, multi-port memory that is shared.)