The C500 microcontroller family usually provides only one on-chip synchronous serialchannel (SSC). If a second SSC is required, an emulation of the missing interface mayhelp to avoid an external hardware solution with additional electronic components.The solution presented in this paper and in the attached source files emulates the mostimportant SSC functions by using optimized SW routines with a performance up to 25KBaud in Slave Mode with half duplex transmission and an overhead less than 60% atSAB C513 with 12 MHz. Due to the implementation in C this performance is not the limitof the chip. A pure implementation in assembler will result in a strong reduction of theCPU load and therefore increase the maximum speed of the interface. In addition,microcontrollers like the SAB C505 will speed up the interface by a factor of two becauseof an optimized architecture compared with the SAB C513.Moreover, this solution lays stress on using as few on-chip hardware resources aspossible. A more excessive consumption of those resources will result in a highermaximum speed of the emulated interface.Due to the restricted performance of an 8 bit microcontroller a pin compatible solution isprovided only; the internal register based programming interface is replaced by a set ofsubroutine calls.The attached source files also contain a test shell, which demonstrates how to exchangeinformation between an on-chip HW-SSC and the emulated SW-SSC via 5 external wiresin different operation modes. It is based on the SAB C513 (Siemens 8 bit microcontroller).A table with load measurements is presented to give an indication for the fraction of CPUperformance required by software for emulating the SSC.
標(biāo)簽： synchronous Emulating serial
上傳時(shí)間： 2014-01-31
上傳用戶：z1191176801
用C51寫(xiě)的普通拼音輸入法源程序代碼:原作使用了一個(gè)二維數(shù)組用以查表，我認(rèn)為這樣比較的浪費(fèi)空間，而且每個(gè)字表的索引地址要手工輸入，效率不高。所以我用結(jié)構(gòu)體將其改寫(xiě)了一下。就是大家現(xiàn)在看到的這個(gè)。 因?yàn)榇a比較的大，共有6,000多漢字，這樣就得要12,000 byte來(lái)存放GB內(nèi)碼，所以也是沒(méi)辦法的.編譯結(jié)果約為3000h,因?yàn)榇蟛糠质撬饕恚a優(yōu)化幾乎無(wú)效。 在Keil C里仿真芯片選用的是華邦的W77E58，它有32k ROM, 256B on-chip RAM, 1K on-chip SRAM (用DPTR1指針尋址,相當(dāng)于有1K的片上x(chóng)data)。條件有限，沒(méi)有上片試驗(yàn)，仿真而已。 打算將其移植到AVR上，但CodeAVRC與IAR EC++在結(jié)構(gòu)體、指針的定義使用上似乎與C51不太一樣，現(xiàn)在還未搞定。還希望在這方面有經(jīng)驗(yàn)的網(wǎng)友能給予指導(dǎo)。 #include<stdio.h> char * py_ime(char *); void main(void){ while(1) { char input_string[]="yI"; xdata char chinese_string[255]; sprintf(chinese_string,"%s",py_ime(input_string)); }}
上傳時(shí)間： 2013-10-30
上傳用戶：cainaifa
基于ADSP-BF561的數(shù)字?jǐn)z像系統(tǒng)設(shè)計(jì)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(hào)處理芯片ADSP-BF561 的數(shù)字?jǐn)z像系統(tǒng)實(shí)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(pán)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?jǐn)z像機(jī);微硬盤(pán);MPEG-4;A/D;D/A中圖分類號(hào):TN948.41文獻(xiàn)標(biāo)識(shí)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?jǐn)z像 系統(tǒng)設(shè)計(jì)
上傳時(shí)間： 2013-11-10
上傳用戶：yl1140vista
PK51是為8051系列單片機(jī)所設(shè)計(jì)的開(kāi)發(fā)工具，支持所有8051系列衍生產(chǎn)品，，支持帶擴(kuò)展存儲(chǔ)器和擴(kuò)展指令集（例如Dallas390/5240/400,Philips 51MX,Analog Devices MicroConverters）的新設(shè)備,以及支持很多公司的一流的設(shè)備和IP內(nèi)核,比如Analog Devices, Atmel, Cypress Semiconductor, Dallas Semiconductor, Goal, Hynix, Infineon, Intel, NXP(founded by Philips), OKI, Silicon Labs,SMSC, STMicroeleectronics,Synopsis, TDK, Temic, Texas Instruments,Winbond等。通過(guò)PK51專業(yè)級(jí)開(kāi)發(fā)工具，可以輕松地了解8051的On-chip peripherals與及其它關(guān)鍵特性。
上傳時(shí)間： 2013-10-09
上傳用戶：1109003457
在綜合分析諧波勵(lì)磁無(wú)刷同步發(fā)電機(jī)勵(lì)磁控制系統(tǒng)的基礎(chǔ)上,對(duì)其勵(lì)磁控制策略進(jìn)行了研究,開(kāi)發(fā)了一套基于DSP( TMS320F2812) 控制的新型柴油發(fā)電機(jī)勵(lì)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(lì)磁,選用交流采樣方式實(shí)時(shí)檢測(cè)各信號(hào)的瞬時(shí)特性,系統(tǒng)仿真結(jié)果以及在1 臺(tái)25 kW 工頻柴油發(fā)電機(jī)上的試驗(yàn)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(jī)對(duì)勵(lì)磁系統(tǒng)的要求。關(guān)鍵詞:勵(lì)磁調(diào)節(jié);模糊PID 控制;數(shù)字信號(hào)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(jī) 勵(lì)磁控制 系統(tǒng)研究
上傳時(shí)間： 2013-10-29
上傳用戶：fxf126@126.com
The Tri-Mode Ethernet MAC (TEMAC) UltraController-II module is a minimal footprint,embedded network processing engine based on the PowerPC™ 405 (PPC405) processor coreand the TEMAC core embedded within a Virtex™-4 FX Platform FPGA. The TEMACUltraController-II module connects to an external PHY through Gigabit Media IndependentInterface (GMII) and Management Data Input/Output (MDIO) interfaces and supports tri-mode(10/100/1000 Mb/s) Ethernet. Software running from the processor cache reads and writesthrough an On-Chip Memory (OCM) interface to two FIFOs that act as buffers between thedifferent clock domains of the PPC405 OCM and the TEMAC.
上傳時(shí)間： 2013-10-26
上傳用戶：yuzsu
工作原理 該裝置電路原理見(jiàn)圖1。由紅外線傳感器、信號(hào)放大電路、電壓比較器、延時(shí)電路和音響報(bào)警電路等組成。紅外線探測(cè)傳感器IC1探測(cè)到前方人體輻射出的紅外線信號(hào)時(shí)，由IC1的②腳輸出微弱的電信號(hào)，經(jīng)三極管VT1等組成第一級(jí)放大電路放大，再通過(guò)C2輸入到運(yùn)算放大器IC2中進(jìn)行高增益、低噪聲放大，此時(shí)由 IC2①腳輸出的信號(hào)已足夠強(qiáng)。IC3作電壓比較器，它的第⑤腳由R10、VD1提供基準(zhǔn)電壓，當(dāng)IC2①腳輸出的信號(hào)電壓到達(dá)IC3的⑥腳時(shí)，兩個(gè)輸入端的電壓進(jìn)行比較， 此時(shí)IC3的⑦腳由原來(lái)的高電平變?yōu)榈碗娖?。IC4為報(bào)警延時(shí)電路，R14和C6組成延時(shí)電路，其時(shí)間約為1分鐘。當(dāng)IC3的⑦腳變?yōu)榈碗娖綍r(shí)，C6通過(guò)VD2放電，此時(shí)IC4的②腳變?yōu)榈碗娖剿cIC4的③腳基準(zhǔn)電壓進(jìn)行比較，當(dāng)它低于其基準(zhǔn)電壓時(shí)，IC4的①腳變?yōu)楦唠娖?，VT2 導(dǎo)通，訊響器BL通電發(fā)出報(bào)警聲。人體的紅外線信號(hào)消失后，IC3的⑦腳又恢復(fù)高電平輸出，此時(shí)VD2截止。由于C6兩端的電壓不能突變， 故通過(guò)R14向 C6緩慢充電，當(dāng)C6兩端的電壓高于其基準(zhǔn)電壓時(shí)，IC4的①腳才變?yōu)榈碗娖?，時(shí)間約為1分鐘，即持續(xù)1分鐘報(bào)警。
標(biāo)簽： 自己動(dòng)手 紅外線 探測(cè) 防盜器
上傳時(shí)間： 2013-12-19
上傳用戶：Breathe0125
The use of the Wind River VxWorks Real-Time Operating System (RTOS) on Virtex™-4embedded PowerPC™ processors continues to be a popular choice for high performanceFPGA designs. The introduction of the Wind River Workbench design environment has enableda new and easier way for designers to control the configuration of the VxWorks kernel. Thisguide shows the steps required to build and configure a ML403 Embedded DevelopmentPlatform to boot and run the VxWorks RTOS. A VxWorks bootloader is created, programmedinto Flash, and used to boot the design. The concepts presented here can be scaled to anyPowerPC enabled development platform.
上傳時(shí)間： 2013-10-26
上傳用戶：agent
第八章 labview的編程技巧 本章介紹局部變量、全局變量、屬性節(jié)點(diǎn)和其他一些有助于提高編程技巧的問(wèn)題，恰當(dāng)?shù)剡\(yùn)用這些技巧可以提高程序的質(zhì)量。 ８．１ 局部變量 嚴(yán)格的語(yǔ)法盡管可以保證程序語(yǔ)言的嚴(yán)密性，但有時(shí)它也會(huì)帶來(lái)一些使用上的不便。在labview這樣的數(shù)據(jù)流式的語(yǔ)言中，將變量嚴(yán)格地分為控制器（Control）和指示器（Indicator），前者只能向外流出數(shù)據(jù)，后者只能接受流入的數(shù)據(jù)，反過(guò)來(lái)不行。在一般的代碼式語(yǔ)言中，情況不是這樣的。例如我們有變量a、b和c，只要需要我們可以將a的值賦給b，將b的值賦給c等等。前面所介紹的labview內(nèi)容中，只有移位積存器即可輸入又可輸出。另外，一個(gè)變量在程序中可能要在多處用到，在圖形語(yǔ)言中勢(shì)必帶來(lái)過(guò)多連線，這也是一件煩人的事。還有其他需要，因此labview引入了局部變量。
上傳時(shí)間： 2013-10-27
上傳用戶：xieguodong1234
減小電磁干擾的印刷電路板設(shè)計(jì)原則 內(nèi) 容 摘要……1 1 背景…1 1.1 射頻源.1 1.2 表面貼裝芯片和通孔元器件.1 1.3 靜態(tài)引腳活動(dòng)引腳和輸入.1 1.4 基本回路……..2 1.4.1 回路和偶極子的對(duì)稱性3 1.5 差模和共?！?.3 2 電路板布局…4 2.1 電源和地…….4 2.1.1 感抗……4 2.1.2 兩層板和四層板4 2.1.3 單層板和二層板設(shè)計(jì)中的微處理器地.4 2.1.4 信號(hào)返回地……5 2.1.5 模擬數(shù)字和高壓…….5 2.1.6 模擬電源引腳和模擬參考電壓.5 2.1.7 四層板中電源平面因該怎么做和不應(yīng)該怎么做…….5 2.2 兩層板中的電源分配.6 2.2.1 單點(diǎn)和多點(diǎn)分配.6 2.2.2 星型分配6 2.2.3 格柵化地.7 2.2.4 旁路和鐵氧體磁珠……9 2.2.5 使噪聲靠近磁珠……..10 2.3 電路板分區(qū)…11 2.4 信號(hào)線……...12 2.4.1 容性和感性串?dāng)_……...12 2.4.2 天線因素和長(zhǎng)度規(guī)則...12 2.4.3 串聯(lián)終端傳輸線…..13 2.4.4 輸入阻抗匹配...13 2.5 電纜和接插件……...13 2.5.1 差模和共模噪聲……...14 2.5.2 串?dāng)_模型……..14 2.5.3 返回線路數(shù)目..14 2.5.4 對(duì)板外信號(hào)I/O的建議14 2.5.5 隔離噪聲和靜電放電ESD .14 2.6 其他布局問(wèn)題……...14 2.6.1 汽車和用戶應(yīng)用帶鍵盤(pán)和顯示器的前端面板印刷電路板...15 2.6.2 易感性布局…...15 3 屏蔽..16 3.1 工作原理…...16 3.2 屏蔽接地…...16 3.3 電纜和屏蔽旁路………………..16 4 總結(jié)…………………………………………17 5 參考文獻(xiàn)………………………17
標(biāo)簽： 印刷電路板 設(shè)計(jì)原則
上傳時(shí)間： 2013-10-22
上傳用戶：a6697238
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