基于單DSP的VoIP模擬電話適配器研究與實現:提出和實現了一種新穎的基于單個通用數字信號處理器(DSP)的VoIP模擬電話適配器方案。DSP的I/O和存儲資源非常有限,通常適于運算密集型應用,不適宜控制密集型應用[5]。該系統高效利用單DSP的I/O和片內外存儲器資源,采用μC/OS-II嵌入式實時操作系統,支持SIP和TCP-UDP/IP協議,通過LAN或者寬帶接入,使普通電話機成為Internet終端,實現IP電話。該系統軟硬件結構緊湊高效,運行穩定,成本低,具有廣闊的應用前景。關鍵詞:模擬電話適配器;IP電話;數字信號處理器;μC/OS-II 【Abstract】This paper presents a VoIP ATA solution based on a single digital signal processor (DSP). DSPs are suitable for arithmetic-intensiveapplication and unsuitable for control-intensive application because of the limitation of I/O and memory resources. This solution is based on a 16-bitfixed-point DSP and μC/OS-II embedded real-time operating system. It makes good use of the limited resources, supports SIP and TCP-UDP/IPprotocol. It can connect the analog telephone to Internet and realize the VoIP application. This system has a great future for its high efficiency andlow cost.【Key words】Analog telephone adapter (ATA); Voice over Internet protocol (VoIP); Digital signal processor (DSP); μC/OS-II Research and Implementation of VoIPATA Based on Single DSP
上傳時間: 2013-11-20
上傳用戶:Wwill
利用SPMC75本身的Flash做數據備份:SPMC75F2413A 32k字的內嵌Flash(embedded Flash)分為兩區:信息區和通用區,在同一時間只能訪問其中的一區。信息區包含64個字,尋址空間為0x8000 ~ 0x803F。地址0x8000為系統選項寄存器P_System_Option。其它地址空間可由用戶自定義重要信息比如:版本控制,日期,版權名稱,項目名稱等等。信息區的內容只有在仿真或燒錄的狀態下才能改變。32k字Flash被劃分為16個頁,每頁2K字,每頁可分為8幀,這樣32K的Flash就可以分成128個幀。只有位于00F000 ~00F7FF區域的頁面在自由運行模式下可以設置為只讀或可讀可寫,其它頁面均為只讀.也就說片內FLASH數據備份區為是0xF000~0xF7FF,備份區為Bank14,最多存儲的數據為2K字。SPMC75F2413A的32K字的內嵌式閃存結構入下圖2-1,圖2-2。
上傳時間: 2013-11-08
上傳用戶:6546544
The XA-S3 is a member of Philips Semiconductors’ XA (eXtended Architecture) family of high performance 16-bit single-chip Microcontrollers. The XA-S3 combines many powerful peripherals on one chip. Therefore, it is suited for general multipurpose high performance embedded control functions.One of the on-chip peripherals is the I2C bus interface. This report describes worked-out driver software (written in C) to program / use the I2C interface of the XA-S3. The driver software, together with a demo program and interface software routines offer the user a quick start in writing a complete I2C - XAS3 system application.
上傳時間: 2013-11-10
上傳用戶:liaofamous
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.
上傳時間: 2013-10-21
上傳用戶:xiaozhiqban
winCE msdn講座 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
上傳時間: 2013-10-31
上傳用戶:jrsoft
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.
上傳時間: 2013-11-10
上傳用戶:1427796291
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
上傳時間: 2013-10-21
上傳用戶:tiantwo
The introduction of Spartan-3™ devices has createdmultiple changes in the evolution of embedded controldesigns and pushed processing capabilities to the “almostfreestage.” With these new FPGAs falling under $20, involume, with over 1 million system gates, and under $5for 100K gate-level units, any design with programmablelogic has a readily available 8- or 16-bit processor costingless than 75 cents and 32-bit processor for less than $1.50.
上傳時間: 2013-12-10
上傳用戶:zgu489
This application note describes how to build a system that can be used for determining theoptimal phase shift for a Double Data Rate (DDR) memory feedback clock. In this system, theDDR memory is controlled by a controller that attaches to either the OPB or PLB and is used inan embedded microprocessor application. This reference system also uses a DCM that isconfigured so that the phase of its output clock can be changed while the system is running anda GPIO core that controls that phase shift. The GPIO output is controlled by a softwareapplication that can be run on a PowerPC® 405 or Microblaze™ microprocessor.
上傳時間: 2013-10-15
上傳用戶:euroford
The Xilinx Zynq-7000 Extensible Processing Platform (EPP) redefines the possibilities for embedded systems, giving system and software architects and developers a flexible platform to launch their new solutions and traditional ASIC and ASSP users an alternative that aligns with today’s programmable imperative. The new class of product elegantly combines an industrystandard ARMprocessor-based system with Xilinx 28nm programmable logic—in a single device. The processor boots first, prior to configuration of the programmable logic. This, along with a streamlined workflow, saves time and effort and lets software developers and hardware designers start development simultaneously.
上傳時間: 2013-11-01
上傳用戶:dingdingcandy