The bus is programable . at this rate the user can program the mcu firmware to configure the correlative registers before using the bus . the user can also change the bus channel in the gpmb when the data of different type is to be transfered . in conclusion , gpmb module provides the communication channel between usb2 . 0 ip core and peripheral 它提供32位可编程接口，用户可以通过usb2 . 0ip核中的mcu固件对内部相关寄存器进行配置来使用这32位总线，并可以在内部的多总线通道中切换，以达成usb2 . 0ip核对外围接口的控制及数据传输，进而完成设备通过usb2 . 0接口ip核与主机通信的功能。
From the development status of the fieldbus control system ( fcs ) , this paper introduces the process of standardization in detail , points out the disadvantages of the multi - fieldbus system , which are bad openness , inefficient and poor flexibilty . at last the " paper presents a new scheme of system integration by means of opc technology 本文从现场总线控制系统的发展现状出发，详细分析了现场总线协议的标准化过程，指出现在多种总线共存的系统存在着开放性，可重用性、灵活性差的缺点，提出利用opc技术实现多总线集成的方法。
