Question

Identify the inputs and outputs of a one-bit binary full adder

2. Create a truth table for the full adder

3. Write an equation for each output as a function of the inputs

4. Minimize (simplify) each equation

Answer 1

Answer:

Given that identify the inputs and outputs of a one bit binary full adder

2)

Truth table for the full adder

	A	B	C input	SUM	C output
0	0	0	0	0	0
1	0	0	1	1	0
2	0	1	0	1	0
3	0	1	1	0	1
4	1	0	0	1	0
5	1	0	1	0	1
6	1	1	0	0	1
7	1	1	1	1	1

3)

An Equation for each output as a function of the inputs

Sum =   

=

C _output =

=

   4) Minimise

SUM

A + B + C _input

For two complement

First obtain is compliment nothing

complement each bit

This will be done by XOR the input with another input 1

and then add 1

3 bit adder / substractor only 2's complement.

B ₂₂ B ₁₂ B ₀₂ - is the 2's complement

Select If select = 0 adder function then B ₂₂ B ₁₂ B ₀₂ = B ₂ B ₁ B ₀

If select = 1 substrator function  

B ₂₂ B ₁₂ B _{02 = 2's complemtary (} B ₂ B ₁ B _{0 )}