Arduino与Proteus仿真实例-74LS138译码器驱动仿真

74LS138译码器驱动仿真

74LS138 是 TTL 逻辑门‘74xx’系列的成员。该芯片专为解码或解复用应用而设计，具有 3 个输入到 8 个输出设置。该设计还使芯片用于高性能存储器解码或数据路由应用，需要非常短的传播延迟时间。在高性能存储器系统中，这些解码器可用于最小化系统解码的影响。芯片的三个使能引脚（其中两个低电平有效，一个高电平有效）减少了扩展时对外部栅极或反相器的需要。 24线解码器无需外接反相器即可实现，32线解码器仅需一个反相器。

在前面的文章中，对74LS138译码器做了介绍，请参考：

8051单片机Proteus仿真与开发实例-74LS138译码器驱动仿真

1、仿真电路原理图

2、仿真代码实现

int C = 4;        // C pin of 74138 is connected to the 11th pin of arduino
int B = 3;        // B pin of 74138 is connected to the 12th pin of arduino
int A = 2;        // A pin of 74138 is connected to the 13th pin of arduino

// the setup routine runs once when you press reset:
void setup() {              
  // initialize the digital pins as an output.
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  // Input 0 0 0 ( 0 in decimal ) in the order C B A. Output will be through Y0
  digitalWrite(A, LOW);  
  digitalWrite(B, LOW);  
  digitalWrite(C, LOW);  
  delay(500);          

  // Input 0 0 1 ( 1 in decimal ) in the order C B A. Output will be through Y1
  digitalWrite(A, HIGH);  
  digitalWrite(B, LOW);  
  digitalWrite(C, LOW);  
  delay(500);

  // Input 0 1 0 ( 2 in decimal ) in the order C B A. Output will be through Y2
  digitalWrite(A, LOW);  
  digitalWrite(B, HIGH);  
  digitalWrite(C, LOW);  
  delay(500);

  // Input 0 1 1 ( 3 in decimal ) in the order C B A. Output will be through Y3
  digitalWrite(A, HIGH);  
  digitalWrite(B, HIGH);  
  digitalWrite(C, LOW);  
  delay(500);

  // Input 1 0 0 ( 4 in decimal ) in the order C B A. Output will be through Y4
  digitalWrite(A, LOW);  
  digitalWrite(B, LOW);  
  digitalWrite(C, HIGH);  
  delay(500);

  // Input 1 0 1 ( 5 in decimal ) in the order C B A. Output will be through Y5
  digitalWrite(A, HIGH);  
  digitalWrite(B, LOW);  
  digitalWrite(C, HIGH);  
  delay(500);

  // Input 1 1 0 ( 6 in decimal ) in the order C B A. Output will be through Y6
  digitalWrite(A, LOW);  
  digitalWrite(B, HIGH);  
  digitalWrite(C, HIGH);  
  delay(500);

  // Input 1 1 1 ( 7 in decimal ) in the order C B A. Output will be through Y7
  digitalWrite(A, HIGH);  
  digitalWrite(B, HIGH);  
  digitalWrite(C, HIGH);  
  delay(500);
}