1C31124G01模拟量电子模块
设备驱动程序是一组相关函数的集合。它包含设备服务子程序和中断处理程序，每个设备服务子程序只处理一种设备或者紧密相关的设备。其目的就是从与设备无关的软件中接受抽象的命令并执行。当执行一条请求时，具体操作是根据控制器驱动程序提供的接口，并利用中断机制去调用中断服务子程序配合设备来完成这个请求。设备程序利用结构file_operations与文件系统联系起来。在Linux下驱动程序装载如图4所示。
1C31124G01模拟量电子模块 HPI驱动程序
HPI接口可用I/O端口方式,也可以用I/O存取方式。系统平台采用I/O存取方式，将HPI访问控制寄存器、数据寄存器、地址寄存器，映射到内存物理地址为0X0C000000开始的空间，通过访问存储器指令对HPI进行操作。HPI具体物理地址定义如下：
#defineHPI_BASE0X0C000000//HPI基地址#define HPD_READ_LOWHPI_BASE+0X0012//读数据寄存器第一字节#define HPA_WRITE_HIGHHPI_BASE+0X000C//写地址寄存器第二字节
在Linux下，类似Windows，程序不能直接访问物理地址。设备驱动程序是内核的一部分，它像内核中其他代码一样运行在内核模式，驱动程序如果出错就会使系统受到严重破坏，因此需要将物理地址映射到内核空间。在Linux下通过virtul_address=(u32)ioremap(HPI_BASE,HPI_LENGTH)实现。驱动程序主要结构如下：
struct file_operations hpi_fops={owner:THIS_MODULE,read: hpi_read,write: hpi_write,poll : hpi_poll,open: hpi_open,release: hpi_release,};
HPI通信协议采用帧结构，由于增强型HPI接口允许访问DSP内部RAM所有空间，系统通信在DSP内部分配2 KB(16位)作为帧缓冲区，读写各1 KB，协议采用一位滑动窗口协议。帧格式如表1所列。微控制器以来微控制器趋向于更多的专用衍生和更多的功能和较低的技术门槛。集成更多功能，更大存储器以及低功耗。
Ethernet in the harsh and dangerous industrial environment.
The switch hangs each port on a backplane bus with high bandwidth (at As the basis of electromechanical system, communication system is the core of connecting various systems and realizing service and information construction.
The whole network communication of the ￠ expressway is composed of the optical fiber ring network as the backbone and the three-layer Gigabit Industrial Ethernet switch supporting the optical fiber ring network as the core. The access points of each station use two-tier (or three-tier) switches to build each service application subnet, and the application subnets are divided by virtual local area network (VLAN) to realize the actual needs of different services. ??
Most tunnels are the characteristics of Chinese roads, especially those in the central and western regions. The local controller set at the tunnel portal in the tunnel control system is mainly used to control the circuits such as fan, lighting and fire pump in the tunnel, as well as the facilities such as brightness detector, variable information board and variable speed limit sign.
The tunnel site is also equipped with control boxes (cabinets) that provide direct manual control functions, such as ventilation and lighting control cabinets. If necessary, the above equipment can also be manually controlled. The local controller can communicate with the workstation in the central control room through the local control network, upload local equipment data, issue the control command of the central control room or store the customized control command of the central control room, and the local controller will control the local equipment regularly.
