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1.4 思考题与习题
1. 说明数字电路和模拟电路的区别及各自特点。
2. 什么是逻辑变量?什么是逻辑函数?
3. 基本逻辑运算有哪几种?每种逻辑运算的逻辑表达式是什么?
4. 什么是逻辑函数的最简与或表达式?
5. 照明电路如图1-28所示,设灯亮L=1,开关A和B闭合为1,试写出灯点亮的逻辑表达式。
6. 用逻辑表达式描述出图1.29中灯L点亮与开关K1、K2、K3动作之间的关系,开关闭合为1。
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0034_0002.jpg?sign=1739282163-W1ld19Rjp0CvrTIkJC7dkxXnwiSoxV7G-0-6d9c590e85218ac928b4693951776499)
图1-28
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0034_0003.jpg?sign=1739282163-oPCrHgDjHGIlAbmpYnwmmFcYcF3Y4ift-0-453cc7bdc11a238486b31e137ffdf305)
图1-29
7. 将下列函数化简为最简的与或表达式。
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0034_0004.jpg?sign=1739282163-9rgQEhdg3hva30c7lnVseN5dB6b9vnPQ-0-da62edeecf6b2eb7ccc3520be297d7fd)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0034_0005.jpg?sign=1739282163-hDe9UaYRlE1m6nvGArLSMLpT475JysWN-0-5064848ccd7e030d4f714e5fa1ddd1c6)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0034_0006.jpg?sign=1739282163-AmSr12U1P5cLBW8wQ9ty7HNxtX0brYzd-0-ff4f0424c56ad71e99283e84b0c70573)
(4)Y=A·B+B+B·C·D
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0034_0007.jpg?sign=1739282163-ljXdiDJrO09MWZcj3bNZ35VFTiBRBq9m-0-77c33b5576250bb64e949015510accb7)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0035_0001.jpg?sign=1739282163-8HKVscduaUPaU6gyOxrYBA7I6N6SbvDP-0-15a9eb2455bb9dee44a19eba7b0ddf38)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0035_0002.jpg?sign=1739282163-ShJddEbsM2LmXTatEETF8EwxXGO1HVtD-0-529aec2465320f7ddcfe503917fad884)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0035_0003.jpg?sign=1739282163-GwLmSTalQunMddc0FNcqJD72Jt8Z3D5j-0-4aa34d8831e70164140705e6987b4abc)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0035_0004.jpg?sign=1739282163-cTKpHafYVdWqqt1XuyvOF3iSz2ZkaSSl-0-1385faa056d39f1501a562a4050572d2)
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0035_0005.jpg?sign=1739282163-v3vJQ7KRpBbczAHUMXjGW2VXiKPHfFbi-0-1ef3b65cb008f971efb6088f4a3b195a)
8. 组合逻辑电路的设计步骤是什么?
9. 设计一个A、B、C三人表决电路。当表决某个提案时,多数人同意则提案通过,同时A具有否决权。用与非门实现电路连接。
10. 在计算机系统中,缓冲器和锁存器各起什么作用?
11. 图1.30为一个扩展模块的地址译码电路,为系统总线信号,低电平允许寻址。已知A15~ A10为全0,请写出74LS138的各个输出引脚(
~
)所对应的地址范围。
![](https://epubservercos.yuewen.com/6A81F4/3590548103311201/epubprivate/OEBPS/Images/figure_0035_0009.jpg?sign=1739282163-2Ov02rbaQ7kSbFNU3AwhG773iGrhnj2i-0-606943068e916b0256ee21c941f65a5e)
图1-30
12. 简述TTL、MOS数字集成电路的特点及其应用范围。