有两种方式可以让设备和应用程序之间联系：1. 通过为设备创建的一个符号链；2. 通过输出到一个接口WDM驱动程序建议使用输出到一个接口而不推荐使用创建符号链的方法。这个接口保证PDO的安全，也保证安全地创建一个惟一的、独立于语言的访问设备的方法。一个应用程序使用Win32APIs来调用设备。在某个Win32 APIs和设备对象的分发函数之间存在一个映射关系。获得对设备对象访问的第一步就是打开一个设备对象的句柄。 用符号链打开一个设备的句柄为了打开一个设备，应用程序需要使用CreateFile。如果该设备有一个符号链出口，应用程序可以用下面这个例子的形式打开句柄：hDevice = CreateFile("\\\\.\\OMNIPORT3", GENERIC_READ | GENERIC_WRITE,FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL ,NULL);文件路径名的前缀“\\.\”告诉系统本调用希望打开一个设备。这个设备必须有一个符号链，以便应用程序能够打开它。有关细节查看有关Kdevice和CreateLink的内容。在上述调用中第一个参数中前缀后的部分就是这个符号链的名字。注意：CreatFile中的第一个参数不是Windows 98/2000中驱动程序(.sys文件)的路径。是到设备对象的符号链。如果使用DriverWizard产生驱动程序，它通常使用类KunitizedName来构成设备的符号链。这意味着符号链名有一个附加的数字，通常是0。例如：如果链接名称的主干是L“TestDevice”那么在CreateFile中的串就该是“\\\\.\\TestDevice0”。如果应用程序需要被覆盖的I/O，第六个参数(Flags)必须或上FILE_FLAG_OVERLAPPED。 使用一个输出接口打开句柄用这种方式打开一个句柄会稍微麻烦一些。DriverWorks库提供两个助手类来使获得对该接口的访问容易一些，这两个类是CDeviceInterface, 和 CdeviceInterfaceClass。CdeviceInterfaceClass类封装了一个设备信息集，该信息集包含了特殊类中的所有设备接口信息。应用程序能有用CdeviceInterfaceClass类的一个实例来获得一个或更多的CdeviceInterface类的实例。CdeviceInterface类是一个单一设备接口的抽象。它的成员函数DevicePath()返回一个路径名的指针，该指针可以在CreateFile中使用来打开设备。下面用一个小例子来显示这些类最基本的使用方法：extern GUID TestGuid;HANDLE OpenByInterface( GUID* pClassGuid, DWORD instance, PDWORD pError){ CDeviceInterfaceClass DevClass(pClassGuid, pError); if (*pError != ERROR_SUCCESS) return INVALID_HANDLE_VALUE; CDeviceInterface DevInterface(&DevClass, instance, pError); if (*pError != ERROR_SUCCESS) return INVALID_HANDLE_VALUE; cout << "The device path is " << DevInterface.DevicePath() << endl; HANDLE hDev; hDev = CreateFile( DevInterface.DevicePath(), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL ); if (hDev == INVALID_HANDLE_VALUE) *pError = GetLastError(); return hDev;} 在设备中执行I/O操作一旦应用程序获得一个有效的设备句柄，它就能使用Win32 APIs来产生到设备对象的IRPs。下面的表显示了这种对应关系。Win32 API DRIVER_FUNCTION_xxxIRP_MJ_xxx KDevice subclass member function CreateFile CREATE Create ReadFile READ Read WriteFile WRITE Write DeviceIoControl DEVICE_CONTROL DeviceControl CloseHandle CLOSECLEANUP CloseCleanUp 需要解释一下设备类成员的Close和CleanUp：CreateFile使内核为设备创建一个新的文件对象。这使得多个句柄可以映射同一个文件对象。当这个文件对象的最后一个用户级句柄被撤销后，I/O管理器调用CleanUp。当没有任何用户级和核心级的对文件对象的访问的时候，I/O管理器调用Close。如果被打开的设备不支持指定的功能，则调用相应的Win32将引起错误（无效功能）。以前为Windows95编写的VxD的应用程序代码中可能会在打开设备的时候使用FILE_FLAG_DELETE_ON_CLOSE属性。在Windows NT/2000中，建议不要使用这个属性，因为它将导致没有特权的用户企图打开这个设备，这是不可能成功的。I/O管理器将ReadFile和WriteFile的buff参数转换成IRP域的方法依赖于设备对象的属性。当设备设置DO_DIRECT_IO标志，I/O管理器将buff锁住在存储器中，并且创建了一个存储在IRP中的MDL域。一个设备可以通过调用Kirp::Mdl来存取MDL。当设备设置DO_BUFFERED_IO标志，设备对象分别通过KIrp::BufferedReadDest或 KIrp::BufferedWriteSource为读或写操作获得buff地址。当设备不设置DO_BUFFERED_IO标志也不设置DO_DIRECT_IO，内核设置IRP 的UserBuffer域来对应ReadFile或WriteFile中的buff参数。然而，存储区并没有被锁住而且地址只对调用进程有效。驱动程序可以使用KIrp::UserBuffer来存取IRP域。对于DeviceIoControl调用，buffer参数的转换依赖于特殊的I/O控制代码，它不在设备对象的特性中。宏CTL_CODE（在winioctl.h中定义）用来构造控制代码。这个宏的其中一个参数指明缓冲方法是METHOD_BUFFERED, METHOD_IN_DIRECT, METHOD_OUT_DIRECT, 或METHOD_NEITHER。下面的表显示了这些方法和与之对应的能获得输入缓冲与输出缓冲的KIrp中的成员函数：Method Input Buffer Parameter Output Buffer Parameter METHOD_BUFFERED KIrp::IoctlBuffer KIrp::IoctlBuffer METHOD_IN_DIRECT KIrp::IoctlBuffer KIrp::Mdl METHOD_OUT_DIRECT KIrp::IoctlBuffer KIrp::Mdl METHOD_NEITHER KIrp::IoctlType3InputBuffer KIrp::UserBuffer 如果控制代码指明METHOD_BUFFERED，系统分配一个单一的缓冲来作为输入与输出。驱动程序必须在向输出缓冲放数据之前拷贝输入数据。驱动程序通过调用KIrp::IoctlBuffer获得缓冲地址。在完成时，I/O管理器从系统缓冲拷贝数据到提供给Ring 3级调用者使用的缓冲中。驱动程序必须在结束前存储拷贝到IRP的Information成员中的数据个数。如果控制代码不指明METHOD_IN_DIRECT或METHOD_OUT_DIRECT，则DeviceIoControl的参数呈现不同的含义。参数InputBuffer被拷贝到一个系统缓冲，这个缓冲驱动程序可以通过调用KIrp::IoctlBuffer。参数OutputBuffer被映射到KMemory对象，驱动程序对这个对象的访问通过调用KIrp::Mdl来实现。对于METHOD_OUT_DIRECT，调用者必须有对缓冲的写访问权限。注意，对METHOD_NEITHER，内核只提供虚拟地址；它不会做映射来配置缓冲。虚拟地址只对调用进程有效。这里是一个用METHOD_BUFFERED的例子：首先，使用宏CTL_CODE来定义一个IOCTL代码：#define IOCTL_MYDEV_GET_FIRMWARE_REV \CTL_CODE (FILE_DEVICE_UNKNOWN,0,METHOD_BUFFERED,FILE_ANY_ACCESS)现在使用一个DeviceIoControl调用：BOOLEAN b;CHAR FirmwareRev[60];ULONG FirmwareRevSize;b = DeviceIoControl(hDevice, IOCTL_MYDEV_GET_VERSION_STRING, NULL, // no input 注意，这里放的是包含有执行操作命令的字符串指针 0, FirmwareRev, //这里是output串指针，存放从驱动程序中返回的字符串。sizeof(FirmwareRev),& FirmwareRevSize, NULL // not overlapped I/O );如果输出缓冲足够大，设备拷贝串到里面并将拷贝的资结束设置到FirmwareRevSize中。在驱动程序中，代码看起来如下所示：const char* FIRMWARE_REV = "FW 16.33 v5";NTSTATUS MyDevice::DeviceControl( KIrp I ){ ULONG fwLength=0; switch ( I.IoctlCode() ) { case IOCTL_MYDEV_GET_FIRMWARE_REV: fwLength = strlen(FIRMWARE_REV)+1; if (I.IoctlOutputBufferSize() >= fwLength) { strcpy((PCHAR)I.IoctlBuffer(),FIRMWARE_REV); I.Information() = fwLength; return I.Complete(STATUS_SUCCESS); } else { } case . . . } }
上传时间： 2013-10-17
上传用户：gai928943
//芯片资料请到www.elecfans.com查找 //DS1820 C51 子程序//这里以11.0592M晶体为例，不同的晶体速度可能需要调整延时的时间//sbit DQ =P2^1;//根据实际情况定义端口 typedef unsigned char byte;typedef unsigned int word; //延时void delay(word useconds){ for(;useconds>0;useconds--);} //复位byte ow_reset(void){ byte presence; DQ = 0; //pull DQ line low delay(29); // leave it low for 480us DQ = 1; // allow line to return high delay(3); // wait for presence presence = DQ; // get presence signal delay(25); // wait for end of timeslot return(presence); // presence signal returned} // 0=presence, 1 = no part //从 1-wire 总线上读取一个字节byte read_byte(void){ byte i; byte value = 0; for (i=8;i>0;i--) { value>>=1; DQ = 0; // pull DQ low to start timeslot DQ = 1; // then return high delay(1); //for (i=0; i<3; i++); if(DQ)value|=0x80; delay(6); // wait for rest of timeslot } return(value);} //向 1-WIRE 总线上写一个字节void write_byte(char val){ byte i; for (i=8; i>0; i--) // writes byte, one bit at a time { DQ = 0; // pull DQ low to start timeslot DQ = val&0x01; delay(5); // hold value for remainder of timeslot DQ = 1; val=val/2; } delay(5);} //读取温度char Read_Temperature(void){ union{ byte c[2]; int x; }temp; ow_reset(); write_byte(0xCC); // Skip ROM write_byte(0xBE); // Read Scratch Pad temp.c[1]=read_byte(); temp.c[0]=read_byte(); ow_reset(); write_byte(0xCC); //Skip ROM write_byte(0x44); // Start Conversion return temp.x/2;}
上传时间： 2013-11-03
上传用户：hongmo
24c16读写驱动程序，//=-------------------------------------------------------------------------------/*模块调用:读数据:read(unsigned int address)写数据:write(unsigned int address,unsigned char dd) dd为要写的 数据字节*///------------------------------------------------------------------------------ sbit sda=P3^0;sbit scl=P3^1; sbit a0=ACC^0; //定义ACC的位，利用ACC操作速度最快sbit a1=ACC^1;sbit a2=ACC^2;sbit a3=ACC^3;sbit a4=ACC^4;sbit a5=ACC^5;sbit a6=ACC^6;sbit a7=ACC^7; //------------------------------------------------------------------------------#pragma disablevoid s24(void) //起始函数{_nop_(); scl=0; sda=1; scl=1; _nop_(); sda=0; _nop_(); _nop_(); scl=0; _nop_(); _nop_(); sda=1;} //------------------------------------------------------------------------------#pragma disablevoid p24(void) //停止函数{sda=0; scl=1; _nop_(); _nop_(); sda=1;} //-----------------------------------------------------------------------------#pragma disableunsigned char rd24(void) /////////////////从24c16读一字节数据{ ACC=0x00;sda=1;scl=1;a7=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a6=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a5=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a4=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a3=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a2=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a1=sda;_nop_();_nop_();_nop_();_nop_();scl=0;scl=1;a0=sda;_nop_();_nop_();_nop_();_nop_();scl=0;sda=1;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0; /// ///////////////24c16的一位回答位。return(ACC);}//------------------------------------------------------------------------------#pragma disablevoid wd24(unsigned char dd) ////////////////向24c16写一字节数据{ sda=1;ACC=dd;sda=a7;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a6;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a5;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a4;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a3;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a2;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a1;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=a0;scl=1;_nop_();_nop_();_nop_();_nop_();scl=0;sda=0;scl=1;//scl=0;(在下面程序中)}//---------------------------------------------------------------------------#pragma disableunsigned char read(unsigned int address){unsigned char dd; s24(); ////////////////////////开始条件 wd24(0xa0); /////////////////////////写器件地址（写命令） _nop_();_nop_();_nop_();_nop_(); scl=0; ///////////////////////////////////接收器件地址确认信号 wd24(address); //////////////////////////// 写数据地址 _nop_();_nop_();_nop_();_nop_(); scl=0;s24(); ///////////////////////////////////开始条件 wd24(0xa1); /////////////////////////////写器件地址（读命令） scl=0; dd=rd24(); //////////////////////////////////读 一字节 p24(); ////////////////////////////////////停止条件 return(dd);}//------------------------------------------------------------------------------#pragma disablevoid write(unsigned int address,unsigned char dd){s24(); /////////////////开始条件 wd24(0xa0); ////////////////////////写器件地址； scl=0; wd24(address); /////////////////////写数据地址 scl=0; wd24(dd); //////////////////////////写dd数据 scl=0; p24(); /////////////////////////停止条件； }
上传时间： 2013-11-18
上传用户：墙角有棵树
This application note covers the design considerations of a system using the performance features of the LogiCORE™ IP Advanced eXtensible Interface (AXI) Interconnect core. The design focuses on high system throughput through the AXI Interconnect core with F MAX and area optimizations in certain portions of the design. The design uses five AXI video direct memory access (VDMA) engines to simultaneously move 10 streams (five transmit video streams and five receive video streams), each in 1920 x 1080p format, 60 Hz refresh rate, and up to 32 data bits per pixel. Each VDMA is driven from a video test pattern generator (TPG) with a video timing controller (VTC) block to set up the necessary video timing signals. Data read by each AXI VDMA is sent to a common on-screen display (OSD) core capable of multiplexing or overlaying multiple video streams to a single output video stream. The output of the OSD core drives the DVI video display interface on the board. Performance monitor blocks are added to capture performance data. All 10 video streams moved by the AXI VDMA blocks are buffered through a shared DDR3 SDRAM memory and are controlled by a MicroBlaze™ processor. The reference system is targeted for the Virtex-6 XC6VLX240TFF1156-1 FPGA on the Xilinx® ML605 Rev D evaluation board
上传时间： 2013-11-14
上传用户：fdmpy
UART 4 UART参考设计，Xilinx提供VHDL代码 uart_vhdl This zip file contains the following folders: \vhdl_source -- Source VHDL files: uart.vhd - top level file txmit.vhd - transmit portion of uart rcvr.vhd - - receive portion of uart \vhdl_testfixture -- VHDL Testbench files. This files only include the testbench behavior, they do not instantiate the DUT. This can easily be done in a top-level VHDL file or a schematic. This folder contains the following files: txmit_tb.vhd -- Test bench for txmit.vhd. rcvr_tf.vhd -- Test bench for rcvr.vhd.
上传时间： 2013-11-07
上传用户：jasson5678
This book is for students and Linux System Administrators. It provides the skills to read, write, and debug Linux shell scripts using bash shell. The book begins by describing Linux and simple scripts to automate frequently executed commands and continues by describing conditional logic, user interaction, loops, menus, traps, and functions.
上传时间： 2014-12-30
上传用户：黄蛋的蛋黄
The NCV7356 is a physical layer device for a single wire data linkcapable of operating with various Carrier Sense Multiple Accesswith Collision Resolution (CSMA/CR) protocols such as the BoschController Area Network (CAN) version 2.0. This serial data linknetwork is intended for use in applications where high data rate is notrequired and a lower data rate can achieve cost reductions in both thephysical media components and in the microprocessor and/ordedicated logic devices which use the network.The network shall be able to operate in either the normal data ratemode or a high-speed data download mode for assembly line andservice data transfer operations. The high-speed mode is onlyintended to be operational when the bus is attached to an off-boardservice node. This node shall provide temporary bus electrical loadswhich facilitate higher speed operation. Such temporary loads shouldbe removed when not performing download operations.The bit rate for normal communications is typically 33 kbit/s, forhigh-speed transmissions like described above a typical bit rate of83 kbit/s is recommended. The NCV7356 features undervoltagelockout, timeout for faulty blocked input signals, output blankingtime in case of bus ringing and a very low sleep mode current.
上传时间： 2013-10-24
上传用户：s蓝莓汁
U 盘作为一种便利的存储设备，可以应用于嵌入式系统中，其应用的基础就是对Linux 的USB Mass Storage 驱动的裁剪，以获得所需的简化的驱动程序。分析了Linux 下的USB mass storage 协议，简化系统中所不需要的代码，使其仅支持基于Bulk-Only 传输模式下的ATAPI 协议的存储设备，从而使嵌入式系统更加精简，对USB mass storage 驱动程序进行了裁剪。经过裁剪的USB Mass Storage 驱动程序移植到三星公司的QT2410E 开发板上并取得成功。
上传时间： 2013-11-23
上传用户：wfl_yy
The LPC2292/2294 microcontrollers are based on a 16/32-bit ARM7TDMI-S CPU with real-time emulation and embedded trace support, together with 256 kB of embedded high-speed flash memory. A 128-bit wide memory interface and a unique accelerator architecture enable 32-bit code execution at the maximum clock rate. For critical code size applications, the alternative 16-bit Thumb mode reduces code by more than 30 pct with minimal performance penalty. With their 144-pin package, low power consumption, various 32-bit timers, 8-channel 10-bit ADC, 2/4 (LPC2294) advanced CAN channels, PWM channels and up to nine external interrupt pins these microcontrollers are particularly suitable for automotive and industrial control applications as well as medical systems and fault-tolerant maintenance buses. The number of available fast GPIOs ranges from 76 (with external memory) through 112 (single-chip). With a wide range of additional serial communications interfaces, they are also suited for communication gateways and protocol converters as well as many other general-purpose applications. Remark: Throughout the data sheet, the term LPC2292/2294 will apply to devices with and without the /00 or /01 suffix. The suffixes /00 and /01 will be used to differentiate from other devices only when necessary.
上传时间： 2014-12-30
上传用户：aysyzxzm
6小时学会labview, labview Six Hour Course – Instructor Notes This zip file contains material designed to give students a working knowledge of labview in a 6 hour timeframe. The contents are: Instructor Notes.doc – this document. labviewIntroduction-SixHour.ppt – a PowerPoint presentation containing screenshots and notes on the topics covered by the course. Convert C to F (Ex1).vi – Exercise 1 solution VI. Convert C to F (Ex2).vi – Exercise 2 solution subVI. Thermometer-DAQ (Ex2).vi – Exercise 2 solution VI. Temperature Monitor (Ex3).vi – Exercise 3 solution VI. Thermometer (Ex4).vi – Exercise 4 solution subVI. Convert C to F (Ex4).vi – Exercise 4 solution subVI. Temperature Logger (Ex4).vi – Exercise 4 solution VI. Multiplot Graph (Ex5).vi – Exercise 5 solution VI. Square Root (Ex6).vi – Exercise 6 solution VI. State Machine 1 (Ex7).vi – Exercise 7 solution VI. The slides can be presented in two three hour labs, or six one hour lectures. Depending on the time and resources available in class, you can choose whether to assign the exercises as homework or to be done in class. If you decide to assign the exercises in class, it is best to assign them in order with the presentation. This way the students can create VI’s while the relevant information is still fresh. The notes associated with the exercise slide should be sufficient to guide the students to a solution. The solution files included are one possible solution, but by no means the only solution.
标签： labview
上传时间： 2013-10-13
上传用户：zjwangyichao
