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?
上传时间： 2020-06-09
上传用户：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.
标签： Foundations Science Data of
上传时间： 2020-06-10
上传用户：shancjb
lm75A温度数字转换器 FPGA读写实验Verilog逻辑源码Quartus工程文件+文档资料,FPGA为CYCLONE4系列中的EP4CE6E22C8. 完整的工程文件，可以做为你的学习设计参考。LM75A 是一个使用了内置带隙温度传感器和模数转换技术的温度数字转换器。它也是一个温度检测器，可提供一个过热检测输出。LM75A 包含许多数据寄存器：配置寄存器用来存储器件的某些配置，如器件的工作模式、OS 工作模式、OS 极性和OS 故障队列等（在功能描述一节中有详细描述）；温度寄存器（Temp），用来存储读取的数字温度；设定点寄存器（Tos & Thyst），用来存储可编程的过热关断和滞后限制，器件通过2 线的串行I2C 总线接口与控制器通信。LM75A 还包含一个开漏输出（OS），当温度超过编程限制的值时该输出有效。LM75A 有3 个可选的逻辑地址管脚，使得同一总线上可同时连接8个器件而不发生地址冲突。LM75A 可配置成不同的工作条件。它可设置成在正常工作模式下周期性地对环境温度进行监控或进入关断模式来将器件功耗降至最低。OS 输出有2 种可选的工作模式：OS 比较器模式和OS 中断模式。OS 输出可选择高电平或低电平有效。故障队列和设定点限制可编程，为了激活OS 输出，故障队列定义了许多连续的故障。温度寄存器通常存放着一个11 位的二进制数的补码，用来实现0.125℃的精度。这个高精度在需要精确地测量温度偏移或超出限制范围的应用中非常有用。正常工作模式下，当器件上电时，OS 工作在比较器模式，温度阈值为80℃，滞后75℃，这时，LM75A就可用作一个具有以上预定义温度设定点的独立的温度控制器。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 ;
上传时间： 2021-10-27
上传用户：
基于FPGA设计的sdram读写测试实验Verilog逻辑源码Quartus工程文件+文档说明，DRAM选用海力士公司的 HY57V2562 型号,容量为的 256Mbit,采用了 54 引脚的TSOP 封装, 数据宽度都为 16 位, 工作电压为 3.3V,并丏采用同步接口方式所有的信号都是时钟信号。FPGA型号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
标签： fpga sdram verilog quartus
上传时间： 2021-12-18
上传用户：
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
标签： pw2330
上传时间： 2022-02-11
上传用户：
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
标签： pw2205
上传时间： 2022-02-11
上传用户：
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
上传时间： 2022-03-04
上传用户：
以AT89S52单片机为控制核心,采用电容降压技术,Buck电路拓扑,PWM驱动模块和功率器件散热设计,通过高速的数据采集、主功率输入输出模块和控制模块,设计一种新型智能车载充电器.在充电过程中,通过负脉冲瞬间放电实现对铅酸蓄电池的再生修复,提高电池的有效容量,延长使用寿命.该充电器体积小、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.
标签： 车载充电器
上传时间： 2022-03-27
上传用户：
随着科技的发展，人们在日常生活中使用的电器越来越多，电子设备的电磁兼容性（EMC）也越来越重要。所以，人们对电子设备的电磁兼容性的要求也越来越严格，越来越规范。而在市场竞争中，如何降低成本、减少设备体积，是各电子设备制造厂家重点研究的课题。通过对开关电源的EMI滤波电路的类别和相应的技术特点进行分析，设计出一种既能提高性能，又能降低成本的滤波电路。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.
上传时间： 2022-04-23
上传用户：
Allegro导出 Gerber文件和钻孔数据文件很多PCB厂家都没有装Allegro软件，所以你不能直接发.brd文件。（很多PCB小厂连ProtelDXP也没有，只支持Protel99）什么是Gerber文件Gerber文件是所有电路设计软件都可以产生的文件，在电子组装行业又称为模版文件（stencil data），在PCB制造业又称为光绘文件。可以说Gerber文件是电子组装业中最通用最广泛的文件格式Gerber文件是EIA的标准格式，分RS274-D和RS274-X两种，其中RS274-X是RS274-D的扩展文件。生产制造部门在条件许可的情况下，应当尽可能要求用户或设计部门提供RS274-X的Gerber文件，这样有利于各工序的生产准备。准备工作为了保证出片的正确性，需要在设计PCB文件之前对一些系统参数进行设置，该设置包括画图的精度，图片的尺寸，动态铺铜的格式。设置画图的精度。在allegro中打开Setup->Drawing Size菜单，调出设置对话框，如图1在对话框中确定User Units选择Mils，Size选择C，这样整个作图区域会大一点，相应的作图范围（Drawing Extents）变为Width：22000.00：Height：17000.00Left X和LeftY为原点坐标。Accuracy选择2，其他根据你的尺寸自行定义。设置完成选择OK按钮，使配置生效。
上传时间： 2022-04-30
上传用户：zhaiyawei
