I can remember buying my first electronic calculator. I was teaching a graduate level statistics course and I had to have a calculator with a square root function. Back in the late 1960s, that was a pretty high-end requirement for a calculator. I managed to purchase one at the “educational discount price” of $149.95! Now, I look down at my desk at an ATmega2560 that is half the size for less than a quarter of the cost and think of all the possibilities built into that piece of hardware. I am amazed by what has happened to everything from toasters to car engines. Who-da-thunk-it 40 years ago?
上傳時間： 2020-06-09
上傳用戶：shancjb
Computer science as an academic discipline began in the 1960’s. Emphasis was on programming languages, compilers, operating systems, and the mathematical theory that supported these areas. Courses in theoretical computer science covered finite automata, regular expressions, context-free languages, and computability. In the 1970’s, the study of algorithms was added as an important component of theory. The emphasis was on making computers useful. Today, a fundamental change is taking place and the focus is more on a wealth of applications. There are many reasons for this change. The merging of computing and communications has played an important role. The enhanced ability to observe, collect, and store data in the natural sciences, in commerce, and in other fields calls for a change in our understanding of data and how to handle it in the modern setting. The emergence of the web and social networks as central aspects of daily life presents both opportunities and challenges for theory.
標簽： Foundations Science Data of
上傳時間： 2020-06-10
上傳用戶：shancjb
lm75A溫度數(shù)字轉(zhuǎn)換器 FPGA讀寫實驗Verilog邏輯源碼Quartus工程文件+文檔資料,FPGA為CYCLONE4系列中的EP4CE6E22C8. 完整的工程文件，可以做為你的學習設計參考。LM75A 是一個使用了內(nèi)置帶隙溫度傳感器和模數(shù)轉(zhuǎn)換技術的溫度數(shù)字轉(zhuǎn)換器。它也是一個溫度檢測器，可提供一個過熱檢測輸出。LM75A 包含許多數(shù)據(jù)寄存器：配置寄存器用來存儲器件的某些配置，如器件的工作模式、OS 工作模式、OS 極性和OS 故障隊列等（在功能描述一節(jié)中有詳細描述）；溫度寄存器（Temp），用來存儲讀取的數(shù)字溫度；設定點寄存器（Tos & Thyst），用來存儲可編程的過熱關斷和滯后限制，器件通過2 線的串行I2C 總線接口與控制器通信。LM75A 還包含一個開漏輸出（OS），當溫度超過編程限制的值時該輸出有效。LM75A 有3 個可選的邏輯地址管腳，使得同一總線上可同時連接8個器件而不發(fā)生地址沖突。LM75A 可配置成不同的工作條件。它可設置成在正常工作模式下周期性地對環(huán)境溫度進行監(jiān)控或進入關斷模式來將器件功耗降至最低。OS 輸出有2 種可選的工作模式：OS 比較器模式和OS 中斷模式。OS 輸出可選擇高電平或低電平有效。故障隊列和設定點限制可編程，為了激活OS 輸出，故障隊列定義了許多連續(xù)的故障。溫度寄存器通常存放著一個11 位的二進制數(shù)的補碼，用來實現(xiàn)0.125℃的精度。這個高精度在需要精確地測量溫度偏移或超出限制范圍的應用中非常有用。正常工作模式下，當器件上電時，OS 工作在比較器模式，溫度閾值為80℃，滯后75℃，這時，LM75A就可用作一個具有以上預定義溫度設定點的獨立的溫度控制器。module LM75_SEG_LED ( //input input sys_clk ,input sys_rst_n ,inout sda_port ,//output output wire seg_c1 ,output wire seg_c2 ,output wire seg_c3 ,output wire seg_c4 ,output reg seg_a ,output reg seg_b ,output reg seg_c ,output reg seg_e ,output reg seg_d ,output reg seg_f ,output reg seg_g ,output reg seg_h , output reg clk_sclk );//parameter define parameter WIDTH = 8;parameter SIZE = 8;//reg define reg [WIDTH-1:0] counter ;reg [9:0] counter_div ;reg clk_50k ;reg clk_200k ;reg sda ;reg enable ;
標簽： lm75a 數(shù)字轉(zhuǎn)換器 fpga verilog
上傳時間： 2021-10-27
上傳用戶：
基于FPGA設計的sdram讀寫測試實驗Verilog邏輯源碼Quartus工程文件+文檔說明，DRAM選用海力士公司的 HY57V2562 型號,容量為的 256Mbit,采用了 54 引腳的TSOP 封裝, 數(shù)據(jù)寬度都為 16 位, 工作電壓為 3.3V,并丏采用同步接口方式所有的信號都是時鐘信號。FPGA型號Cyclone4E系列中的EP4CE6F17C8，Quartus版本17.1。timescale 1ps/1psmodule top(input clk,input rst_n,output[1:0] led,output sdram_clk, //sdram clockoutput sdram_cke, //sdram clock enableoutput sdram_cs_n, //sdram chip selectoutput sdram_we_n, //sdram write enableoutput sdram_cas_n, //sdram column address strobeoutput sdram_ras_n, //sdram row address strobeoutput[1:0] sdram_dqm, //sdram data enable output[1:0] sdram_ba, //sdram bank addressoutput[12:0] sdram_addr, //sdram addressinout[15:0] sdram_dq //sdram data);parameter MEM_DATA_BITS = 16 ; //external memory user interface data widthparameter ADDR_BITS = 24 ; //external memory user interface address widthparameter BUSRT_BITS = 10 ; //external memory user interface burst widthparameter BURST_SIZE = 128 ; //burst sizewire wr_burst_data_req; // from external memory controller,write data request ,before data 1 clockwire wr_burst_finish; // from external memory controller,burst write finish
標簽： fpga sdram verilog quartus
上傳時間： 2021-12-18
上傳用戶：
PW2330 develops a high efficiency synchronous step down DC-DC converter capable of delivering3A output current. PW2330 operates over a wide input voltage range from 4.5V to 30V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss. PW2330 adopts the proprietary instant PWM architecture to achieve fast transient responsesfor high step down applications and high efficiency at light loads. In addition, it operates atpseudo-constant frequency of 500kHz under continuous conduction mode to minimize the size ofinductor and capacitor
標簽： pw2330
上傳時間： 2022-02-11
上傳用戶：
PW2205 develops a high efficiency synchronous step-down DC-DC converter capable of delivering5A output current. PW2205 operates over a wide input voltage range from 4.5V to 30V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss.PW2205 adopts the instant PWM architecture to achieve fast transient responses for high step downapplications and high efficiency at light loads. In addition, it operates at pseudo-constant frequencyof 500kHz under continuous conduction mode to minimize the size of inductor and capacitor
標簽： pw2205
上傳時間： 2022-02-11
上傳用戶：
Single chip TFT-LCD Controller/Driver with On-chip Frame Memory (FM) Display Resolution: 240*RGB (H) *320(V) Frame Memory Size: 240 x 320 x 18-bit = 1,382,400 bits LCD Driver Output Circuits- Source Outputs: 240 RGB Channels- Gate Outputs: 320 Channels- Common Electrode Output Display Colors (Color Mode)- Full Color: 262K, RGB=(666) max., Idle Mode Off- Color Reduce: 8-color, RGB=(111), Idle Mode On Programmable Pixel Color Format (Color Depth) for Various Display Data input Format- 12-bit/pixel: RGB=(444)- 16-bit/pixel: RGB=(565)- 18-bit/pixel: RGB=(666) MCU Interface- Parallel 8080-series MCU Interface (8-bit, 9-bit, 16-bit & 18-bit)- 6/16/18 RGB Interface(VSYNC, HSYNC, DOTCLK, ENABLE, DB[17:0])- Serial Peripheral Interface(SPI Interface)- VSYNC Interface
上傳時間： 2022-03-04
上傳用戶：
以AT89S52單片機為控制核心,采用電容降壓技術,Buck電路拓撲,PWM驅(qū)動模塊和功率器件散熱設計,通過高速的數(shù)據(jù)采集、主功率輸入輸出模塊和控制模塊,設計一種新型智能車載充電器.在充電過程中,通過負脈沖瞬間放電實現(xiàn)對鉛酸蓄電池的再生修復,提高電池的有效容量,延長使用壽命.該充電器體積小、速度快、效率高、可靠性好.With AT89S52 single chip computer as the control core,a new type of intelligent car-carried charger was designed by using capacitance step-down technology,Buck circuit topology,PWM driving module and power device heat dissipation design,through high-speed data acquisition,main power input and output module and control module.In the charging process,the regeneration and repair of lead-acid batteries are realized by instantaneous discharge of negative pulse,which improves the effective capacity of batteries and prolongs their service life.The charger has the advantages of small size,fast speed,high efficiency and good reliability.
標簽： 車載充電器
上傳時間： 2022-03-27
上傳用戶：
隨著科技的發(fā)展，人們在日常生活中使用的電器越來越多，電子設備的電磁兼容性（EMC）也越來越重要。所以，人們對電子設備的電磁兼容性的要求也越來越嚴格，越來越規(guī)范。而在市場競爭中，如何降低成本、減少設備體積，是各電子設備制造廠家重點研究的課題。通過對開關電源的EMI濾波電路的類別和相應的技術特點進行分析，設計出一種既能提高性能，又能降低成本的濾波電路。With the development of technology, appliances people use in their daily lives, more and more electronic devices electromagnetic compatibility （ EMC ） has become increasingly important. So, people electromagnetic compatibility requirements of electronic devices have become increasingly stringent, more and more standardized. The competition in the market, how to reduce costs, reduce equipment size, is the subject of the electronic equipment manufacturer focused on research. Through the technical characteristics of the respective category and the EMI filter circuit switching power supply is analyzed both designed to improve a performance of the filter circuit can reduce the cost.
上傳時間： 2022-04-23
上傳用戶：
Allegro導出 Gerber文件和鉆孔數(shù)據(jù)文件很多PCB廠家都沒有裝Allegro軟件，所以你不能直接發(fā).brd文件。（很多PCB小廠連ProtelDXP也沒有，只支持Protel99）什么是Gerber文件Gerber文件是所有電路設計軟件都可以產(chǎn)生的文件，在電子組裝行業(yè)又稱為模版文件（stencil data），在PCB制造業(yè)又稱為光繪文件。可以說Gerber文件是電子組裝業(yè)中最通用最廣泛的文件格式Gerber文件是EIA的標準格式，分RS274-D和RS274-X兩種，其中RS274-X是RS274-D的擴展文件。生產(chǎn)制造部門在條件許可的情況下，應當盡可能要求用戶或設計部門提供RS274-X的Gerber文件，這樣有利于各工序的生產(chǎn)準備。準備工作為了保證出片的正確性，需要在設計PCB文件之前對一些系統(tǒng)參數(shù)進行設置，該設置包括畫圖的精度，圖片的尺寸，動態(tài)鋪銅的格式。設置畫圖的精度。在allegro中打開Setup->Drawing Size菜單，調(diào)出設置對話框，如圖1在對話框中確定User Units選擇Mils，Size選擇C，這樣整個作圖區(qū)域會大一點，相應的作圖范圍（Drawing Extents）變?yōu)閃idth：22000.00：Height：17000.00Left X和LeftY為原點坐標。Accuracy選擇2，其他根據(jù)你的尺寸自行定義。設置完成選擇OK按鈕，使配置生效。
上傳時間： 2022-04-30
上傳用戶：zhaiyawei
