CDMA has been quite successful as a second-generation cellular system,having achieved widespread use in particular in North America and Korea by the turn of the twenty-first century.
個程序實現(xiàn)了距離矢量路由算法,又稱Bellman-Ford算法,使用java編程實現(xiàn).-This process achieved a distance vector routing algorithm, also known as Bellman-Ford algorithm
個程序實現(xiàn)了距離矢量路由算法,又稱Bellman-Ford算法,使用java編程實現(xiàn).-This process achieved a distance vector routing algorithm, also known as Bellman-Ford algorithm
為解決直流逆變交流的問題，有效地利用能源，讓電源輸出最大功率，設計了高性能的基于IR2101最大功率跟蹤逆變器，并以SPMC75F2413A單片機作為主控制器。高電壓、高速功率的MOSFET或IGBT驅動器IR2101采用高度集成的電平轉換技術，同時上管采用外部自舉電容上電，能夠穩(wěn)定高效地驅動MOS管。該逆變器可以實現(xiàn)DC/AC的轉換，最大功率點的跟蹤等功能。實際測試結果表明，該逆變器系統(tǒng)具有跟蹤能力強，穩(wěn)定性高，反應靈敏等特點，該逆變器不僅可應用于普通的電源逆變系統(tǒng)，而且可應用于光伏并網發(fā)電的逆變系統(tǒng)，具有廣泛的市場前景。
Abstract:
To solve the problem of DC-AC inverter， and to utilize solar energy more efficiently， the design of maximum power point tracking inverter based on IR2101 was achieved with a high-performance， which can make the system output power maximum. SPMC75F2413A was adopted as main controller. IR2101 is a high voltage， high speed power MOSFET and IGBT driver. It adopted highly integrated voltage level transforming technology， and an external bootstrap capacitor was used， which could drive MOS tube efficiently and stably. Many functions are achieved in the system， such as DC/AC conversion， maximun power point tracking， etc. The actual test result shows that the inverter system has characteristics of strong tracking ability， high stability and reacting quickly. The design can not only be used in ordinary power inverter system， but also be used in photovoltaic power inverter system. The design has certain marketing prospects
現(xiàn)有基于MAX7219芯片的數(shù)碼管驅動電路只適用于小尺寸LED，為擴展其使用范圍，在介紹動態(tài)顯示芯片MAX7219功能的基礎上，提出了一個基于該芯片的8位高亮度8英寸數(shù)碼管驅動電路。電路保留了MAX7219芯片的功能強大、編程簡單等優(yōu)點，通過74LS273鎖存器和ULN2803達林頓驅動器，實現(xiàn)了對任意大尺寸數(shù)碼管提供較高電壓和電流驅動的靜態(tài)顯示，并亮度可調。
Abstract:
The existing display-driving circuit based on MAX7219 was only applicable to small-size LED. To expand its use, based on the function introduction of dynamic display chip MAX7219, a display-driving circuit for high-brightness 8-bit LED with the size of 8-inch was proposed. The advantages of MAX7219 were retained, such as powerful function and simple programming. Static display with adjustable brightness for large-size LED with higher voltage and current was achieved with the help of 74LS273 and ULN2803.
針對目前使用的RS232接口數(shù)字化B超鍵盤存在PC主機啟動時不能設置BIOS，提出一種PS2鍵盤的設計方法。基于W78E052D單片機，采用8通道串行A/D轉換器設計了8個TGC電位器信息采集電路，電位器位置信息以鍵盤掃描碼序列形式發(fā)送，正交編碼器信號通過XC9536XL轉換為單片機可接收的中斷信號，軟件接收到中斷信息后等效處理成按鍵。結果表明，在滿足開機可設置BIOS同時，又可實現(xiàn)超聲特有功能，不需要專門設計驅動程序，接口簡單，成本低。
Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot， this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller，designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter， potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU， software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot， ultrasound specific functionality can be achieved at the same time， it does not require specially designed driver，the interface is simple and low cost.
單片機作為一種微型計算機，其內部具有一定的存儲單元（8031除外），但由于其內部存儲單元及端口有限，很多情況下難以滿足實際需求。為此介紹一種新的擴展方法，將數(shù)據(jù)線與地址線合并使用，通過軟件控制的方法實現(xiàn)數(shù)據(jù)線與地址線功能的分時轉換，數(shù)據(jù)線不僅用于傳送數(shù)據(jù)信號，還可作為地址線、控制線，用于傳送地址信號和控制信號，從而實現(xiàn)單片機與存儲器件的有效連接。以單片機片外256KB數(shù)據(jù)存儲空間的擴展為例，通過該擴展方法，僅用10個I/O端口便可實現(xiàn)，與傳統(tǒng)的擴展方法相比，可節(jié)約8個I/O端口。
Abstract:
As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
在深入了解Flash存儲器的基礎上，采用單片機自動檢測存儲器無效塊。主要通過讀取每一塊的第1、第2頁內容，判斷該塊的好壞，并給出具體的實現(xiàn)過程，以及部分關鍵的電路原理圖和C語言程序代碼。該設計最終實現(xiàn)單片機自動檢測Flash壞塊的功能，并通過讀取ID號檢測Flash的性能，同時該設計能夠存儲和讀取1GB數(shù)據(jù)。
Abstract:
On the basis of in-depth understanding the Flash chips，this paper designs a new program which using the SCM to detect the invalid block.Mainly through reading the data of the first and second page to detect the invalid block.Specific implementation procedure was given,and the key circuit schematic diagram and C language program code was introduced.This design achieved the function of using the MCU checks the invalid block finally，and increased the function by reading the ID number of Flash to get the performance of the memory.And the design also can write and read1GB data
