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  • Reading and Writing iButtons v

    Abstract: This application note explains the hardware of different types of 1-Wire® interfaces and software examples adapted to this hardware with a focus on serial ports. Depending on the types of iButtons required for a project and the type of computer to be used, the most economical interface is easily found. The hardware examples shown are basically two different types: 5V general interface and 12V RS-232 interface. Within the 5V group a common printed circuit board could be used for all circuits described. The variations can be achieved by different populations of components. The same principal is used for the 12V RS-232 interface. The population determines if it is a Read all or a Read/Write all type of interface. There are other possible circuit implementations to create a 1-Wire interface. The circuits described in this application note cover many different configurations. For a custom application, one of the described options can be adapted to meet individual needs.

    标签: iButtons Reading Writing and

    上传时间: 2013-10-29

    上传用户:long14578

  • CAN与RS232转换节点的设计与实现

    CAN与RS232转换节点的设计与实现 介绍将CAN总线接口与RS232总线接口相互转换的设计方法和2种总线电平转换关系,实现CAN总线与各模块的接口设计,制定了相应的软硬件设计方案,并给出软件设计流程图以及部分硬件设计原理图。为CAN总线与RS232总线互联提供了一种方法,对CAN总线与RS232总线接口设备的互联和广泛应用的实现具有重要意义。关键词:CAN总线;RS-232总线;串行通信Design and Realization of CAN and RS232 Transformation NodeZHOU Wei, CHENG Xiao-hong(Information Institute, Wuhan University of Technology, Wuhan 430070)【Abstract】This paper introduces one design method of the CAN bus interface and the RS232 bus interface interconversion, emphasizes two kindof bus level transformation relations, realizes the CAN bus and various modules connection design, formulates the design proposal of correspondingsoftware and hardware, and gives the flow chart of software design as well as the partial schematic diagram of hardware design. It providesonemethod for the CAN bus and the RS232 bus interconnection, has the vital significance to widespread application realization of the CAN busand theRS232 bus interface equipment interconnection.【Key words】CAN bus; RS-232 bus; serial communication

    标签: CAN 232 RS 转换

    上传时间: 2013-11-04

    上传用户:leesuper

  • 驱动程序与应用程序的接口

    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 . . .   } }

    标签: 驱动程序 应用程序 接口

    上传时间: 2013-10-17

    上传用户:gai928943

  • 串行下载线的原理图-电路图

    串行下载线的原理图 SI Prog - Serial Interface for PonyProg

    标签: 串行 下载线 原理图 电路图

    上传时间: 2013-11-09

    上传用户:zhishenglu

  • 3.3v看门狗芯片

    The STWD100 watchdog timer circuits are self-contained devices which prevent systemfailures that are caused by certain types of hardware errors (non-responding peripherals,bus contention, etc.) or software errors (bad code jump, code stuck in loop, etc.).The STWD100 watchdog timer has an input, WDI, and an output, WDO (see Figure 2). Theinput is used to clear the internal watchdog timer periodically within the specified timeoutperiod, twd (see Section 3: Watchdog timing). While the system is operating correctly, itperiodically toggles the watchdog input, WDI. If the system fails, the watchdog timer is notreset, a system alert is generated and the watchdog output, WDO, is asserted (seeSection 3: Watchdog timing).The STWD100 circuit also has an enable pin, EN (see Figure 2), which can enable ordisable the watchdog functionality. The EN pin is connected to the internal pull-downresistor. The device is enabled if the EN pin is left floating.

    标签: 3.3 看门狗 芯片

    上传时间: 2013-10-22

    上传用户:taiyang250072

  • 一款监视串口和并口使用的小软件.

    (Portmon is an application that lets you monitor serial and parallel activity on your local system, or any computer on the network that you can reach via TCP/IP. It is the most powerful tool available for tracking down port-related configuration problems and analyzing application port usage.)

    标签: 监视 串口 并口 软件

    上传时间: 2013-11-07

    上传用户:1412904892

  • Xilinx UltraScale:新一代架构满足您的新一代架构需求(EN)

      中文版详情浏览:http://www.elecfans.com/emb/fpga/20130715324029.html   Xilinx UltraScale:The Next-Generation Architecture for Your Next-Generation Architecture    The Xilinx® UltraScale™ architecture delivers unprecedented levels of integration and capability with ASIC-class system- level performance for the most demanding applications.   The UltraScale architecture is the industr y's f irst application of leading-edge ASIC architectural enhancements in an All Programmable architecture that scales from 20 nm planar through 16 nm FinFET technologies and beyond, in addition to scaling from monolithic through 3D ICs. Through analytical co-optimization with the X ilinx V ivado® Design Suite, the UltraScale architecture provides massive routing capacity while intelligently resolving typical bottlenecks in ways never before possible. This design synergy achieves greater than 90% utilization with no performance degradation.   Some of the UltraScale architecture breakthroughs include:   • Strategic placement (virtually anywhere on the die) of ASIC-like system clocks, reducing clock skew by up to 50%    • Latency-producing pipelining is virtually unnecessary in systems with massively parallel bus architecture, increasing system speed and capability   • Potential timing-closure problems and interconnect bottlenecks are eliminated, even in systems requiring 90% or more resource utilization   • 3D IC integration makes it possible to build larger devices one process generation ahead of the current industr y standard    • Greatly increased system performance, including multi-gigabit serial transceivers, I/O, and memor y bandwidth is available within even smaller system power budgets   • Greatly enhanced DSP and packet handling   The Xilinx UltraScale architecture opens up whole new dimensions for designers of ultra-high-capacity solutions.

    标签: UltraScale Xilinx 架构

    上传时间: 2013-11-13

    上传用户:瓦力瓦力hong

  • XAPP503-针对Xilinx器件的SVF和XSVF文件格式

    This application note provides users with a general understanding of the SVF and XSVF fileformats as they apply to Xilinx devices. Some familiarity with IEEE STD 1149.1 (JTAG) isassumed. For information on using Serial Vector Format (SVF) and Xilinx Serial Vector Format(XSVF) files in embedded programming applications

    标签: Xilinx XAPP XSVF 503

    上传时间: 2013-10-21

    上传用户:tiantwo

  • XAPP098 - Spartan FPGA低成本、高效率串行配置

    This application note shows how to achieve low-cost, efficient serial configuration for Spartan FPGA designs. The approachrecommended here takes advantage of unused resources in a design, thereby reducing the cost, part count, memory size,and board space associated with the serial configuration circuitry. As a result, neither processor nor PROM needs to be fullydedicated to performing Spartan configuration.In particular, information is provided on how the idle processing time of an on-board controller can be used to loadconfiguration data from an off-board source. As a result, it is possible to upgrade a Spartan design in the field by sending thebitstream over a network.

    标签: Spartan XAPP FPGA 098

    上传时间: 2014-08-16

    上传用户:adada

  • Virtex-5 GTP Transceiver Wizar

    The LogiCORE™ GTP Wizard automates the task of creating HDL wrappers to configure the high-speed serial GTP transceivers in Virtex™-5 LXT and SXT devices. The menu-driven interface allows one or more GTP transceivers to be configured using pre-definedtemplates for popular industry standards, or from scratch, to support a wide variety of custom protocols.The Wizard produces a wrapper, an example design, and a testbench for rapid integration and verification of the serial interface with your custom function Features• Creates customized HDL wrappers to configureVirtex-5 RocketIO™ GTP transceivers• Users can configure Virtex-5 GTP transceivers toconform to industry standard protocols usingpredefined templates, or tailor the templates forcustom protocols• Included protocol templates provide support for thefollowing specifications: Aurora, CPRI, FibreChannel 1x, Gigabit Ethernet, HD-SDI, OBSAI,OC3, OC12, OC48, PCI Express® (PCIe®), SATA,SATA II, and XAUI• Automatically configures analog settings• Each custom wrapper includes example design, testbench; and both implementation and simulation scripts

    标签: Transceiver Virtex Wizar GTP

    上传时间: 2013-10-23

    上传用户:leyesome