七段字符显示器

1组合逻辑电路第4章CombinatorialLogicCircuitsAmultiplexer(MUX)isadevicethatallowsdigitalinformationfromseveralsourcestoberoutedontoasinglelinefortransmissionoverthatlinetoacommondestination.Thebasicmultiplexerhasseveraldata-inputlinesandasingleoutputline.Italsohasdata-selectinputs,whichpermitdigitaldataonanyoneoftheinputstobeswitchedtotheoutputline.Multiplexersarealsoknownasdataselectors.2发光二极管LED(LightEmittingDiode)材料；砷化镓，磷化镓，磷砷化镓单个LED的工作电流5~20mA，工作电压1.5~3V。响应时间<100nS。R+5VLED七段字符显示器LED点阵显示器3七段字符显示器共阴极共阳极a=1b=1d=1e=1g=1c=0f=044.3.4显示译码器LED七段字符显示器和液晶显示器都可以用TTL或CMOS集成电路干脆驱动。须要用显示译码器把要显示的字符的BCD码译成七段字符显示器所须要的驱动信号。BCD码七段码显示译码器七段字符显示器BCD码七段码附加限制信号5BCD七段字符显示译码器（代码转换器）7448111100001111400000001111151101001101113110001000111210011001101111011000010110110011110019111111100018000011111107111110001106110110110105110011000104100111111003101101101002000011010001011111100000字形YgYfYeYdYcYbYaA0A1A2A3数字输出输入62.BCD七段字符显示译码器 （代码转换器）7448111100001111400000001111151101001101113110001000111210011001101111011000010110110011110019111111100018000011111107111110001106110110110105110011000104100111111003101101101002000011010001011111100000字形YgYfYeYdYcYbYaA0A1A2A3数字输出输入A3A2A1A000010001111010011110011100001110Ya的卡诺图Yb的卡诺图A3A2A1A000010001111011101110101100001110Yc的卡诺图A3A2A1A000010001111011111011001100101110Yd的卡诺图A3A2A1A000010001111010011101011001111110Ye的卡诺图A3A2A1A000010001111010000101001001011110Yf的卡诺图A3A2A1A000010001111010110001111101001110Yg的卡诺图A3A2A1A0000100011110001111011111011111107Ya的卡诺图A3A2A1A000010001111010011110011100001110Yb的卡诺图A3A2A1A0000100011110111011101011000011108Yc的卡诺图Yd的卡诺图A3A2A1A000010001111011111011001100101110A3A2A1A0000100011110100111010110011111109Ye的卡诺图Yf的卡诺图A3A2A1A000010001111010000101001001011110A3A2A1A00001000111101011000111110100111010Yg的卡诺图A3A2A1A000010001111000111101111101111110用7448驱动七段字符显示器的连接方法117448的附加限制信号：灯测试输入

当时，Ya~Yg全部置为1灭零输入当，时，则灭灯灭灯输入/灭零输出1.输入信号，称灭灯输入控制端：无论输入状态是什么，数码管熄灭2.输出信号，称灭零输出端：只有当输入，且灭零输入信号时，才给出低电平因此表示译码器将本来应该显示的零熄灭了12例：利用和的配合，实现多位显示系统的灭零控制整数部分：最高位的0，而且灭掉以后，输出作为次高位的输入信号小数部分：最低位的0，而且灭掉以后，输出作为次低位的输入信号灭零输入灭灯输入/灭零输出1134.4.1数据选择器Multiplexer4选1数据选择器MUX00MUX01MUX10MUX11数据输入数据输出地址输入4.4数据选择器144.4.1数据选择器Multiplexer4选1数据选择器MUX简化真值表A1A0D0D1D2D3F0000011001011××0地址输入使能端数据输入15集成“双四选一”数据选择器，74HC153例：A1A0D10D11D12D13Y10000011001011××0A1A0D20D21D22D23Y20000011001011××0地址16用两个“四选一”接成“八选一”“四选一”只有2位地址输入，从四个输入中选中一个“八选一”的八个数据须要3位地址代码指定其中任何一个八选一数据选择器的逻辑函数：17用两个“四选一”接成“八选一”≥11A2=0，A2=1，地址数据数据184.4.2用数据选