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
CAN與RS232轉(zhuǎn)換節(jié)點的設(shè)計與實現(xiàn) 介紹將CAN總線接口與RS232總線接口相互轉(zhuǎn)換的設(shè)計方法和2種總線電平轉(zhuǎn)換關(guān)系，實現(xiàn)CAN總線與各模塊的接口設(shè)計，制定了相應(yīng)的軟硬件設(shè)計方案，并給出軟件設(shè)計流程圖以及部分硬件設(shè)計原理圖。為CAN總線與RS232總線互聯(lián)提供了一種方法，對CAN總線與RS232總線接口設(shè)備的互聯(lián)和廣泛應(yīng)用的實現(xiàn)具有重要意義。關(guān)鍵詞：CAN總線；RS-232總線；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
標(biāo)簽： CAN 232 RS 轉(zhuǎn)換
上傳時間： 2013-11-04
上傳用戶：leesuper
三種方法讀取鍵值 使用者設(shè)計行列鍵盤介面，一般常採用三種方法讀取鍵值。 中斷式 在鍵盤按下時產(chǎn)生一個外部中斷通知CPU，並由中斷處理程式通過不同位址讀資料線上的狀態(tài)判斷哪個按鍵被按下。 本實驗採用中斷式實現(xiàn)使用者鍵盤介面。 掃描法 對鍵盤上的某一行送低電位，其他為高電位，然後讀取列值，若列值中有一位是低，表明該行與低電位對應(yīng)列的鍵被按下。否則掃描下一行。 反轉(zhuǎn)法 先將所有行掃描線輸出低電位，讀列值，若列值有一位是低表明有鍵按下；接著所有列掃描線輸出低電位，再讀行值。 根據(jù)讀到的值組合就可以查表得到鍵碼。4x4鍵盤按4行4列組成如圖電路結(jié)構(gòu)。按鍵按下將會使行列連成通路，這也是見的使用者鍵盤設(shè)計電路。 //-----------4X4鍵盤程序--------------// uchar keboard(void) { uchar xxa,yyb,i,key; if((PINC&0x0f)!=0x0f) //是否有按鍵按下 {delayms(1); //延時去抖動 if((PINC&0x0f)!=0x0f) //有按下則判斷 { xxa=~(PINC|0xf0); //0000xxxx DDRC=0x0f; PORTC=0xf0; delay_1ms(); yyb=~(PINC|0x0f); //xxxx0000 DDRC=0xf0; //復(fù)位 PORTC=0x0f; while((PINC&0x0f)!=0x0f) //按鍵是否放開 { display(data); } i=4; //計算返回碼 while(xxa!=0) { xxa=xxa>>1; i--; } if(yyb==0x80) key=i; else if(yyb==0x40) key=4+i; else if(yyb==0x20) key=8+i; else if(yyb==0x10) key=12+i; return key; //返回按下的鍵盤碼 } } else return 17; //沒有按鍵按下 }
上傳時間： 2013-11-12
上傳用戶：a673761058
基于ADSP-BF561的數(shù)字攝像系統(tǒng)設(shè)計Design of Digital Video Camera System Based on Digital Signal ProcessorADSP-BF561（浙江大學(xué) 信息與通信工程研究所，浙江 杭州 310027） 馬海杰, 劉云海摘要：介紹了基于ADI雙核的數(shù)字信號處理芯片ADSP-BF561 的數(shù)字攝像系統(tǒng)實現(xiàn)方案。系統(tǒng)包括硬件和軟件兩部分，硬件主要有ADSP-BF561及其外圍電路、音視頻模數(shù)/數(shù)模轉(zhuǎn)換、CF卡/微硬盤接口等部分。軟件主要有操作系統(tǒng)及音視頻編解碼算法等部分。關(guān)鍵詞：ADSP-BF561 ;數(shù)字攝像機;微硬盤;MPEG-4;A/D;D/A中圖分類號:TN948.41文獻標(biāo)識碼:AAbstract: An implementation of digital video camera system based on ADI dual core digital signal processor ADSP-BF561 is introduced. The system can be divided into two parts——hardware and software design. The hardware design includes ADSP-BF561 and perpheral apparatus, A/D,D/A, CF card or Microdrive and so on. The software includes operating system , audio and video coding algorithm.Key words: ADSP-BF561; digital video camera; microdrive; MPEG-4;A/D;D/A
標(biāo)簽： ADSP-BF 561 數(shù)字攝像 系統(tǒng)設(shè)計
上傳時間： 2013-11-10
上傳用戶：yl1140vista
摘 要:用一種新的思路和方法,先計算低通、再計算高通濾波器的有關(guān)參數(shù),然后組合成帶通濾波器.關(guān)鍵詞:濾波器;參數(shù);新思路中圖分類號: TN713. 5 文獻識別碼:B 文章編號:1008 - 1666 (1999) 04 - 0089 - 03A New Consideration of the Band Filter’s CalculationGuo Wencheng( S hao Yang B usiness and Technology school , S haoyang , Hunan ,422000 )Abstract :This essay deals with a new method of calculating the band filters - first calculatingthe relevant parameters of low - pass filters ,then calculating the ones of high - pass filters.Key words :filter ; parameters ;new considercation八十年代后,信息產(chǎn)業(yè)得到了迅猛發(fā)展. 帶通濾波器在微波通信、廣播電視和精密儀器設(shè)備中得到了廣泛應(yīng)用. 帶通濾波器性能的優(yōu)劣,對提高接收機信噪比,防止鄰近信道干擾,提高設(shè)備的技術(shù)指標(biāo),有著十分重要的意義.我在長期的教學(xué)實踐中,用切比雪夫型方法設(shè)計、計算出寬帶濾波器集中參數(shù)元件的數(shù)據(jù). 該濾波器可運用在檢測微波頻率的儀器和其他設(shè)備中. 再將其思路和計算方法介紹給大家,供參考.
標(biāo)簽： 帶通濾波器設(shè)計 計算
上傳時間： 2014-12-28
上傳用戶：Yukiseop
在綜合分析諧波勵磁無刷同步發(fā)電機勵磁控制系統(tǒng)的基礎(chǔ)上,對其勵磁控制策略進行了研究,開發(fā)了一套基于DSP( TMS320F2812) 控制的新型柴油發(fā)電機勵磁控制系統(tǒng),該系統(tǒng)采用參數(shù)自適應(yīng)模糊PID 控制勵磁,選用交流采樣方式實時檢測各信號的瞬時特性,系統(tǒng)仿真結(jié)果以及在1 臺25 kW 工頻柴油發(fā)電機上的試驗結(jié)果證明了該控制器具有較好的電壓調(diào)節(jié)特性,系統(tǒng)穩(wěn)態(tài)和暫態(tài)性能完全滿足發(fā)電機對勵磁系統(tǒng)的要求。關(guān)鍵詞:勵磁調(diào)節(jié);模糊PID 控制;數(shù)字信號處理器;交流采樣 Abstract :According to the general analysis of the excitation cont rol system of the harmonious wave excitation brushless synchronous generator and it s characteristics ,a new type of diesel generator excitation cont rol system based on DSP( TMS320F2812) was designed. An adaptive fuzzy PID cont rol of excitation is used in this system. To detect the t ransient characteristics of the signals in a timely manner ,AC sampling was applied.The system simulation result s and the testing result s f rom a 25 kW diesel generator (50 Hz) can prove that the voltage regulation characteristics of the excitation cont rol system are very well ,and both the steadyOstate performance and the t ransient performance of the generator are also good.Key words :excitation cont rol ;fuzzy PID cont rol ;digital signal processor (DSP) ;AC sampling
標(biāo)簽： DSP 柴油發(fā)電機 勵磁控制 系統(tǒng)研究
上傳時間： 2013-10-29
上傳用戶：fxf126@126.com
針對運行中火車測速運用多普勒效應(yīng)采用DSP 設(shè)計雷達測速系統(tǒng)并闡述了其基本設(shè)計思想與工作原理給出系統(tǒng)硬件軟件設(shè)計結(jié)構(gòu)和原理圖改善了原有光電測速精度提高了系統(tǒng)工作穩(wěn)定性和可靠性經(jīng)實驗證明DSP 采集板工作穩(wěn)定測速效果好關(guān)鍵詞DSP; 雷達測速; 多普勒效應(yīng) On Board DSP-Based Radar Speed Measurement System TANG Wei, SUN Zhi-fang, CHEN Quan (Dept.of computer Science,Yangtze University,Jingzhou 434023,China)Abstract: This paper presents a DSP-based train speed measurement by using Doppler radar. The structure of the system is introduced.The hardware and software are also discussed.Key words: DSP; rader speed measurement; doppler principle
標(biāo)簽： DSP 車載 系統(tǒng)設(shè)計 雷達測速
上傳時間： 2013-10-27
上傳用戶：003030
The exacting technological demands created byincreasing bandwidth requirements have given riseto significant advances in FPGA technology thatenable engineers to successfully incorporate highspeedI/O interfaces in their designs. One aspect ofdesign that plays an increasingly important role isthat of the FPGA package. As the interfaces get fasterand wider, choosing the right package has becomeone of the key considerations for the systemdesigner.
上傳時間： 2013-10-22
上傳用戶：1234xhb
波長信號的解調(diào)是實現(xiàn)光纖光柵傳感網(wǎng)絡(luò)的關(guān)鍵，基于現(xiàn)有的光纖光柵傳感器解調(diào)方法，提出一種基于FPGA的雙匹配光纖光柵解調(diào)方法，此系統(tǒng)是一種高速率、高精度、低成本的解調(diào)系統(tǒng)，并且通過引入雙匹配光柵有效地克服了雙值問題同時擴大了檢測范圍。分析了光纖光柵的測溫原理并給出了該方案軟硬件設(shè)計，綜合考慮系統(tǒng)的解調(diào)精度和FPGA的處理速度給出了基于拉格朗日的曲線擬合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulation inadequate， a two-match fiber grating demodulation method was presented. This system is a high-speed， high precision， low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
標(biāo)簽： FPGA 光纖光柵 解調(diào)系統(tǒng)
上傳時間： 2014-07-24
上傳用戶：caiguoqing
L2TP（Layer Two tunneling Protocol）是實現(xiàn)二層隧道VPN（Virtual Private Network）的主要技術(shù)，有L2TPV2和L2TPV3兩個協(xié)議標(biāo)準(zhǔn)；為了進一步提高私有網(wǎng)絡(luò)的安全性，本文研究了VPN和L2TP隧道技術(shù)的基本實現(xiàn)技術(shù)，并在現(xiàn)有L2TPV2協(xié)議非對稱工作模型的基礎(chǔ)上實現(xiàn)了向下兼容的支持對稱工作模型的L2TPV3協(xié)議，并對系統(tǒng)的功能和性能進行了測試和分析，測試結(jié)果顯示該實現(xiàn)方案能夠正常完成L2TPV3隧道的建立以及協(xié)議報文的收發(fā)，且系統(tǒng)性能穩(wěn)定。
標(biāo)簽： L2TPV3
上傳時間： 2013-10-31
上傳用戶：iven
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