The 87C576 includes two separate methods of programming theEPROM array, the traditional modified Quick-Pulse method, and anew On-Board Programming technique (OBP).Quick Pulse programming is a method using a number of DEvicepins in parallel (see Figure 1) and is the traditional way in which87C51 family members have been programmed. The Quick-Pulsemethod supports the following programming functions:– program USER EPROM– verify USER EPROM– program KEY EPROM– program security bits– verify security bits– read signature bytesThe Quick-Pulse method is quite easily suited to standardprogramming equipment as evidenced by the numerous vendors of87C51 compatible programmers on the market today. Onedisadvantage is that this method is not well suited to programming inthe embedded application because of the large number of signallines that must be isolated from the application. In addition, parallelsignals from a programmer would need to be cabled to theapplication’s circuit board, or the application circuit board wouldneed to have logic built-in to perform the programming functions.These requirements have generally made in-circuit programmingusing the modified Quick Pulse method impractical in almost all87C51 family applications.
上传时间： 2013-10-21
上传用户：xiaozhiqban
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
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.
上传时间： 2013-10-22
上传用户：taiyang250072
winCE msdn讲座 XP Embedded Now and the future Windows XP Embedded Developmentand Deployment Model OverviewWindows XP Embedded Component ModelWindows XP Embedded Studio Tools Microsoft WindowsXP Embedded Product Highlights Componentized version of Windows XP Professional~ 12,000 components and updates as of Service Pack 2Flexible localizationSame binaries and API as Windows XP ProfessionalHotfixes and service packsEmbedded Enabling FeaturesRuns on standard PC hardwareSupports boot on hard drives, compact flash, DiskOnChipand read-only mediaSupport for remote install and remote bootHeadless DEvice and remote management supportIntegration with Microsoft management tools
上传时间： 2013-10-31
上传用户：jrsoft
The PL2303 USB to Serial adapter is your smart and convenient accessory forconnecting RS-232 serial DEvices to your USB-equipped Windows host computer. Itprovides a bridge connection with a standard DB 9-pin male serial port connector inone end and a standard Type-A USB plug connector on the other end. You simplyattach the serial DEvice onto the serial port of the cable and plug the USB connectorinto your PC USB port. It allows a simple and easy way of adding serial connectionsto your PC without having to go thru inserting a serial card and traditional portconfiguration.This USB to Serial adapter is ideal for connecting modems, cellular phones, PDAs,digital cameras, card readers and other serial DEvices to your computer. It providesserial connections up to 1Mbps of data transfer rate. And since USB does not requireany IRQ resource, more DEvices can be attached to the system without the previoushassles of DEvice and resource conflicts.Finally, the PL-2303 USB to Serial adapter is a fully USB Specification compliantDEvice and therefore supports advanced power management such as suspend andresume operations as well as remote wakeup. The PL-2303 USB Serial cable adapteris designed to work on all Windows operating systems.
上传时间： 2013-11-01
上传用户：ghostparker
用单片机配置FPGA—PLD设计技巧 Configuration/Program Method for Altera DEvice Configure the FLEX DEvice You can use any Micro-Controller to configure the FLEX DEvice–the main idea is clocking in ONE BITof configuration data per CLOCK–start from the BIT 0The total Configuration time–e.g. 10K10 need 15K byte configuration file•calculation equation–10K10* 1.5= 15Kbyte–configuration time for the file itself•15*1024*8*clock = 122,880Clock•assume the CLOCK is 4MHz•122,880*1/4Mhz=30.72msec
上传时间： 2013-10-09
上传用户：a67818601
The AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer with 8Kbytes of Flash programmable and erasable read only memory (PEROM). The DEviceis manufactured using Atmel’s high-density nonvolatile memory technology and iscompatible with the industry-standard 80C51 and 80C52 instruction set and pinout.The on-chip Flash allows the program memory to be reprogrammed in-system or by aconventional nonvolatile memory programmer. By combining a versatile 8-bit CPUwith Flash on a monolithic chip, the Atmel AT89C52 is a powerful microcomputerwhich provides a highly-flexible and cost-effective solution to many embedded controlapplications.
上传时间： 2013-11-10
上传用户：1427796291
设计了一种采用TI公司的C5000系列定点DSP 芯片TMS320VC5509和ADI DEvice公司的2通道的、软件可选的、双极性输入的、最高转换速率是1MSpS、12位的带符号的逐次逼近型串行AD7322的数据采集系统，并阐述了该系统的主要硬件电路的搭建原理、连接方法以及采集过程。
上传时间： 2013-11-18
上传用户：天诚24
This overview guide describes all the peripherals available for TMS320x28xx and TMS320x28xxx DEvices.Section 2 shows the peripherals used by each DEvice. Section 3 provides descriptions of the peripherals.You can download the peripheral guide by clicking on the literature number, which is linked to the portable document format (pdf) file.
上传时间： 2013-11-21
上传用户：HGH77P99
Abstract: Designers who must interface 1-Wire temperature sensors with Xilinx field-programmable gate arrays(FPGAs) can use this reference design to drive a DS28EA00 1-Wire slave DEvice. The downloadable softwarementioned in this document can also be used as a starting point to connect other 1-Wire slave DEvices. The systemimplements a 1-Wire master connected to a UART and outputs temperature to a PC from the DS28EA00 temperaturesensor. In addition, high/low alarm outputs are displayed from the DS28EA00 PIO pins using LEDs.
标签： PicoBlaze Create Master Xilinx
上传时间： 2013-11-05
上传用户：a6697238
