# seven segment display driver circuit problem

#### copper_pipe

Joined Sep 30, 2014
18
Hi all,

Been given an assignment today and Im having some trouble with it. The purpose of the assignment is to add two, two bit unsigned binary numbers together A0,A1, B0 and B1 and will display the resulting valu ein decimal number format on a seven segment display.

I have done out the truth tables correctly I think but Im unsure about the circuit schematic. There are seven binary outputs A to g.

Appreciate any help

Thanks
.

#### WBahn

Joined Mar 31, 2012
30,072
As this appears to be homework, you need to show your best attempt to solve the problem. We can then see what you are doing right and wrong and help you spot the errors and get back on track.

#### shteii01

Joined Feb 19, 2010
4,644
Ok.
I am adding two two bit binary numbers.
Worsed case scenario is that I will have answer containing 3 bits. The third bit is for carry over.
Since I have 3 bits, 2^3=8.
So the largest value my 7 segment will show is 8. Which means that I need one 7 segment display unit.

#### joeyd999

Joined Jun 6, 2011
5,287
Ok.
I am adding two two bit binary numbers.
Worsed case scenario is that I will have answer containing 3 bits. The third bit is for carry over.
Since I have 3 bits, 2^3=8.
So the largest value my 7 segment will show is 8. Which means that I need one 7 segment display unit.
To me, this sounds like a purely combinatorial logic problem. 4 inputs, 7 outputs. He needs 7 kmaps and done.

#### shteii01

Joined Feb 19, 2010
4,644
To me, this sounds like a purely combinatorial logic problem. 4 inputs, 7 outputs. He needs 7 kmaps and done.
It sounded like OP actually need to build the circuit...
- 4 inputs
- 3 outputs
- then binary to decimal decoder ic which also acts as 7 segment driver (or, like you said, combinatorial logic to translate 3 inputs to 7 outputs to drive 7 led is 7 segment display)

#### joeyd999

Joined Jun 6, 2011
5,287
...combinatorial logic to translate 3 inputs to 7 outputs...
I see no need for a middle man.