Combinational Logic - Adders and Subtractors

A description on how to design a half adder, a full adder and a multi-bit ripple carry adder. This video also describes how to create a subtractor circuit using the fact that A-B = A+(-B)...so a subtractor can be made from an adder if one of the inputs is negated.

Category:

Education

Tags:

• Digital logic
• combinational logic
• adder
• subtractor
• twos complement

[tarbidian]

Thanks for the comments! Currently, no plans for VHDL tutorials, the course I am teaching now doesn't cover it, maybe in the future...

[MGApcPro]

Thanks now my minecraft calculator can subtract :D

[chalisload]

A million Thanks to you , I am understanding now, only if my professor at school could be so thorough i would be so happy . Thanks thanks I need to start attending the College Of YouTube....

[frettbuzz13]

I missed my lecture on adders and subtractors and this helped. Thanks for the great video!

[TheNickTheHunter]

I should transfer my tuition for my course to you O_o ahahaha

[killZtheterrannoob]

I should transfer my tuition for my course to you O_o ahahaha

[Jackle512]

Thanks a lot - very helpful



[Recursyn]

Exam is tomorrow, I'm on the verge of giving up... Any help?

[MGApcPro]

How do you get it to subtract below 0... like 2 - 3 = -1 ?

[Recursyn]

Whenever I try to do it myself I get to (A XOR B) + (B XOR C) + (A XOR C). I'm not sure if I'm even along the right lines. I was really understanding it up until this point, and I've hit a brick wall and can no longer grasp the rest.

[Recursyn]

Would you perhaps be able to show a solution on how to do the simplifying "exercises" left to ourselves? I'm not sure how you reach the answer you do, and I have no-one to ask as my lecturer, as nice as he is, isn't very helpful.