2012TI杯陜西賽題H題,2012TI杯陜西賽題B題--頻率補償電路.
上傳時間： 2013-10-07
上傳用戶：ysystc670
高的工作電壓高達100V N雙N溝道MOSFET同步驅(qū)動 The D810DCDC is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The D810DCDC uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor. A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifi er provides very fast line and load transient response. Large 1Ω gate drivers allow the D810DCDC to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. Integrated bias control generates gate drive power from the input supply during start-up and when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher effi ciency.
上傳時間： 2013-10-24
上傳用戶：wd450412225
When a system designer specifies a nonisolated dc/dc powermodule, considering the needed input voltage range isequally as important as considering the required performanceattributes and features. Generally, nonisolated moduleshave either a narrow or a wide input voltage range. Narrowinputmodules typically have a nominal input voltage of3.3, 5, or 12 V. For systems that operate from a tightlyregulated input bus—such as those that do not use batterybackup—a narrow-input module is often adequate sincethe input remains fairly stable.Offering greater flexibility, wide-input modules operatewithin a range of 7 to 36 V, which includes the popular12- or 24-V industrial bus. This enables a single module tobe used for generating multiple voltages. These modulesare ideal for industrial controls, HVAC systems, vehicles,medical instrumentation, and other applications that usea loosely regulated distribution bus. In addition, systemspowered by a rectifier/battery charger with lead-acidbattery backup almost always require wide-input modules.System designers who choose power supplies may wantto take a close look at the latest generation of wide-inputdc/dc modules.
標簽： Wide-input modules offer dc
上傳時間： 2014-12-24
上傳用戶：dragonhaixm
PSHLY-B回路電阻測試儀介紹
上傳時間： 2013-11-05
上傳用戶：木子葉1
針對目前使用的RS232接口數(shù)字化B超鍵盤存在PC主機啟動時不能設(shè)置BIOS，提出一種PS2鍵盤的設(shè)計方法。基于W78E052D單片機，采用8通道串行A/D轉(zhuǎn)換器設(shè)計了8個TGC電位器信息采集電路，電位器位置信息以鍵盤掃描碼序列形式發(fā)送，正交編碼器信號通過XC9536XL轉(zhuǎn)換為單片機可接收的中斷信號，軟件接收到中斷信息后等效處理成按鍵。結(jié)果表明，在滿足開機可設(shè)置BIOS同時，又可實現(xiàn)超聲特有功能，不需要專門設(shè)計驅(qū)動程序，接口簡單，成本低。 Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot， this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller，designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter， potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU， software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot， ultrasound specific functionality can be achieved at the same time， it does not require specially designed driver，the interface is simple and low cost.
上傳時間： 2013-10-10
上傳用戶：asdfasdfd
有兩種方式可以讓設(shè)備和應(yīng)用程序之間聯(lián)系：1. 通過為設(shè)備創(chuàng)建的一個符號鏈；2. 通過輸出到一個接口WDM驅(qū)動程序建議使用輸出到一個接口而不推薦使用創(chuàng)建符號鏈的方法。這個接口保證PDO的安全，也保證安全地創(chuàng)建一個惟一的、獨立于語言的訪問設(shè)備的方法。一個應(yīng)用程序使用Win32APIs來調(diào)用設(shè)備。在某個Win32 APIs和設(shè)備對象的分發(fā)函數(shù)之間存在一個映射關(guān)系。獲得對設(shè)備對象訪問的第一步就是打開一個設(shè)備對象的句柄。 用符號鏈打開一個設(shè)備的句柄為了打開一個設(shè)備，應(yīng)用程序需要使用CreateFile。如果該設(shè)備有一個符號鏈出口，應(yīng)用程序可以用下面這個例子的形式打開句柄：hDevice = CreateFile("\\\\.\\OMNIPORT3", GENERIC_READ | GENERIC_WRITE,FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL ,NULL);文件路徑名的前綴“\\.\”告訴系統(tǒng)本調(diào)用希望打開一個設(shè)備。這個設(shè)備必須有一個符號鏈，以便應(yīng)用程序能夠打開它。有關(guān)細節(jié)查看有關(guān)Kdevice和CreateLink的內(nèi)容。在上述調(diào)用中第一個參數(shù)中前綴后的部分就是這個符號鏈的名字。注意：CreatFile中的第一個參數(shù)不是Windows 98/2000中驅(qū)動程序(.sys文件)的路徑。是到設(shè)備對象的符號鏈。如果使用DriverWizard產(chǎn)生驅(qū)動程序，它通常使用類KunitizedName來構(gòu)成設(shè)備的符號鏈。這意味著符號鏈名有一個附加的數(shù)字，通常是0。例如：如果鏈接名稱的主干是L“TestDevice”那么在CreateFile中的串就該是“\\\\.\\TestDevice0”。如果應(yīng)用程序需要被覆蓋的I/O，第六個參數(shù)(Flags)必須或上FILE_FLAG_OVERLAPPED。 使用一個輸出接口打開句柄用這種方式打開一個句柄會稍微麻煩一些。DriverWorks庫提供兩個助手類來使獲得對該接口的訪問容易一些，這兩個類是CDeviceInterface, 和 CdeviceInterfaceClass。CdeviceInterfaceClass類封裝了一個設(shè)備信息集，該信息集包含了特殊類中的所有設(shè)備接口信息。應(yīng)用程序能有用CdeviceInterfaceClass類的一個實例來獲得一個或更多的CdeviceInterface類的實例。CdeviceInterface類是一個單一設(shè)備接口的抽象。它的成員函數(shù)DevicePath()返回一個路徑名的指針，該指針可以在CreateFile中使用來打開設(shè)備。下面用一個小例子來顯示這些類最基本的使用方法：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;} 在設(shè)備中執(zhí)行I/O操作一旦應(yīng)用程序獲得一個有效的設(shè)備句柄，它就能使用Win32 APIs來產(chǎn)生到設(shè)備對象的IRPs。下面的表顯示了這種對應(yīng)關(guān)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 需要解釋一下設(shè)備類成員的Close和CleanUp：CreateFile使內(nèi)核為設(shè)備創(chuàng)建一個新的文件對象。這使得多個句柄可以映射同一個文件對象。當這個文件對象的最后一個用戶級句柄被撤銷后，I/O管理器調(diào)用CleanUp。當沒有任何用戶級和核心級的對文件對象的訪問的時候，I/O管理器調(diào)用Close。如果被打開的設(shè)備不支持指定的功能，則調(diào)用相應(yīng)的Win32將引起錯誤（無效功能）。以前為Windows95編寫的VxD的應(yīng)用程序代碼中可能會在打開設(shè)備的時候使用FILE_FLAG_DELETE_ON_CLOSE屬性。在Windows NT/2000中，建議不要使用這個屬性，因為它將導(dǎo)致沒有特權(quán)的用戶企圖打開這個設(shè)備，這是不可能成功的。I/O管理器將ReadFile和WriteFile的buff參數(shù)轉(zhuǎn)換成IRP域的方法依賴于設(shè)備對象的屬性。當設(shè)備設(shè)置DO_DIRECT_IO標志，I/O管理器將buff鎖住在存儲器中，并且創(chuàng)建了一個存儲在IRP中的MDL域。一個設(shè)備可以通過調(diào)用Kirp::Mdl來存取MDL。當設(shè)備設(shè)置DO_BUFFERED_IO標志，設(shè)備對象分別通過KIrp::BufferedReadDest或 KIrp::BufferedWriteSource為讀或?qū)懖僮鳙@得buff地址。當設(shè)備不設(shè)置DO_BUFFERED_IO標志也不設(shè)置DO_DIRECT_IO，內(nèi)核設(shè)置IRP 的UserBuffer域來對應(yīng)ReadFile或WriteFile中的buff參數(shù)。然而，存儲區(qū)并沒有被鎖住而且地址只對調(diào)用進程有效。驅(qū)動程序可以使用KIrp::UserBuffer來存取IRP域。對于DeviceIoControl調(diào)用，buffer參數(shù)的轉(zhuǎn)換依賴于特殊的I/O控制代碼，它不在設(shè)備對象的特性中。宏CTL_CODE（在winioctl.h中定義）用來構(gòu)造控制代碼。這個宏的其中一個參數(shù)指明緩沖方法是METHOD_BUFFERED, METHOD_IN_DIRECT, METHOD_OUT_DIRECT, 或METHOD_NEITHER。下面的表顯示了這些方法和與之對應(yīng)的能獲得輸入緩沖與輸出緩沖的KIrp中的成員函數(shù)：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 如果控制代碼指明METHOD_BUFFERED，系統(tǒng)分配一個單一的緩沖來作為輸入與輸出。驅(qū)動程序必須在向輸出緩沖放數(shù)據(jù)之前拷貝輸入數(shù)據(jù)。驅(qū)動程序通過調(diào)用KIrp::IoctlBuffer獲得緩沖地址。在完成時，I/O管理器從系統(tǒng)緩沖拷貝數(shù)據(jù)到提供給Ring 3級調(diào)用者使用的緩沖中。驅(qū)動程序必須在結(jié)束前存儲拷貝到IRP的Information成員中的數(shù)據(jù)個數(shù)。如果控制代碼不指明METHOD_IN_DIRECT或METHOD_OUT_DIRECT，則DeviceIoControl的參數(shù)呈現(xiàn)不同的含義。參數(shù)InputBuffer被拷貝到一個系統(tǒng)緩沖，這個緩沖驅(qū)動程序可以通過調(diào)用KIrp::IoctlBuffer。參數(shù)OutputBuffer被映射到KMemory對象，驅(qū)動程序?qū)@個對象的訪問通過調(diào)用KIrp::Mdl來實現(xiàn)。對于METHOD_OUT_DIRECT，調(diào)用者必須有對緩沖的寫訪問權(quán)限。注意，對METHOD_NEITHER，內(nèi)核只提供虛擬地址；它不會做映射來配置緩沖。虛擬地址只對調(diào)用進程有效。這里是一個用METHOD_BUFFERED的例子：首先，使用宏CTL_CODE來定義一個IOCTL代碼：#define IOCTL_MYDEV_GET_FIRMWARE_REV \CTL_CODE (FILE_DEVICE_UNKNOWN,0,METHOD_BUFFERED,FILE_ANY_ACCESS)現(xiàn)在使用一個DeviceIoControl調(diào)用：BOOLEAN b;CHAR FirmwareRev[60];ULONG FirmwareRevSize;b = DeviceIoControl(hDevice, IOCTL_MYDEV_GET_VERSION_STRING, NULL, // no input 注意，這里放的是包含有執(zhí)行操作命令的字符串指針 0, FirmwareRev, //這里是output串指針，存放從驅(qū)動程序中返回的字符串。sizeof(FirmwareRev),& FirmwareRevSize, NULL // not overlapped I/O );如果輸出緩沖足夠大，設(shè)備拷貝串到里面并將拷貝的資結(jié)束設(shè)置到FirmwareRevSize中。在驅(qū)動程序中，代碼看起來如下所示：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 . . . } }
標簽： 驅(qū)動程序 應(yīng)用程序 接口
上傳時間： 2013-10-17
上傳用戶：gai928943
TKS仿真器B系列快速入門
上傳時間： 2013-10-31
上傳用戶：aix008
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.
上傳時間： 2013-10-24
上傳用戶：s藍莓汁
一個簡單好用的B+樹算法實現(xiàn)
上傳時間： 2015-01-04
上傳用戶：縹緲
一個用Basic實現(xiàn)的B-Tree算法
上傳時間： 2013-12-30
上傳用戶：ccclll
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