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1. OBJECTIVE

The objective of this lab exercise is to design and implement a binary adder.

 

2. EQUIPMENT

1. PAD-234
2. Selected SN7400 series integrated circuits

1. DISCUSSION

One of the things that led to the "digital revolution" was the ability to perform complex mathematical operations using a computer. During this lab we will see how it is possible to design a circuit to perform one such operation – adding two numbers together.

 

2. EXERCISE

Using TTL logic, design a circuit using individual logic gates to implement the adder.   

          Your circuit should be capable of taking two 2-digit inputs and displaying the resulting sum (which may be as many as three digits). For example:

       101

    + 011

---------

     1000

And in general:

   C₁

   X₁ X₀

+ Y₁ Y₀

---

C₂ S₁ S₀

Where C₁ is the carry to the two’s position.

1. Prepare separate truth tables for the 1’s and the 2’s positions.
2. Identify all IC pin connections (i.e., prepare a logic diagram with pin numbers and an IC diagram.
3. Build the circuit and verify the operation.