1C31124G01模擬量電子模塊
設(shè)備驅(qū)動程序是一組相關(guān)函數(shù)的集合。它包含設(shè)備服務(wù)子程序和中斷處理程序，每個設(shè)備服務(wù)子程序只處理一種設(shè)備或者緊密相關(guān)的設(shè)備。其目的就是從與設(shè)備無關(guān)的軟件中接受抽象的命令并執(zhí)行。當(dāng)執(zhí)行一條請求時，具體操作是根據(jù)控制器驅(qū)動程序提供的接口，并利用中斷機制去調(diào)用中斷服務(wù)子程序配合設(shè)備來完成這個請求。設(shè)備程序利用結(jié)構(gòu)file_operations與文件系統(tǒng)聯(lián)系起來。在Linux下驅(qū)動程序裝載如圖4所示。
1C31124G01模擬量電子模塊 HPI驅(qū)動程序
HPI接口可用I/O端口方式,也可以用I/O存取方式。系統(tǒng)平臺采用I/O存取方式，將HPI訪問控制寄存器、數(shù)據(jù)寄存器、地址寄存器，映射到內(nèi)存物理地址為0X0C000000開始的空間，通過訪問存儲器指令對HPI進行操作。HPI具體物理地址定義如下：
#defineHPI_BASE0X0C000000//HPI基地址#define HPD_READ_LOWHPI_BASE+0X0012//讀數(shù)據(jù)寄存器第一字節(jié)#define HPA_WRITE_HIGHHPI_BASE+0X000C//寫地址寄存器第二字節(jié)
在Linux下，類似Windows，程序不能直接訪問物理地址。設(shè)備驅(qū)動程序是內(nèi)核的一部分，它像內(nèi)核中其他代碼一樣運行在內(nèi)核模式，驅(qū)動程序如果出錯就會使系統(tǒng)受到嚴重破壞，因此需要將物理地址映射到內(nèi)核空間。在Linux下通過virtul_address=(u32)ioremap(HPI_BASE,HPI_LENGTH)實現(xiàn)。驅(qū)動程序主要結(jié)構(gòu)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通信協(xié)議采用幀結(jié)構(gòu)，由于增強型HPI接口允許訪問DSP內(nèi)部RAM所有空間，系統(tǒng)通信在DSP內(nèi)部分配2 KB(16位)作為幀緩沖區(qū)，讀寫各1 KB，協(xié)議采用一位滑動窗口協(xié)議。幀格式如表1所列。微控制器以來微控制器趨向于更多的專用衍生和更多的功能和較低的技術(shù)門檻。集成更多功能，更大存儲器以及低功耗。
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.
