Half Adder / Full Adder / Half Subtractor / Full Subtractor:
AIM: To realize
LEARNING OBJECTIVE:
- To realize the adder and subtractor circuits using basic gates and universal gates
- To realize full adder using two half adders
- To realize a full subtractor using two half subtractors
COMPONENTS REQUIRED:
- IC 7400
- IC 7408
- IC 7486
- IC 7432
- Patch Cords & IC Trainer Kit
THEORY:
Half-Adder:
A combinational logic circuit that performs the addition of two data bits, A and B, is called a half-adder. Addition will result in two output bits; one of which is the sum bit,
S, and the other is the carry bit, C.
| TURTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | S = A ⊕ B | C = AB |
| 0 | 0 | 0 | 0 |
| 0 | 1 | 1 | 0 |
| 1 | 0 | 1 | 0 |
| 1 | 1 | 0 | 1 |
BASIC GATE
OUTPUT
HALF ADDER USING NAND
HALF ADDER USING NOR
Full-Adder:
The half-adder does not take the carry bit from its previous stage into account.
This carry bit from its previous stage is called carry-in bit. A combinational logic circuit that
adds two data bits, A and B, and a carry-in bit, Cin , is called a full-adder.
| TURTH TABLE | ||||
|---|---|---|---|---|
| INPUT | OUTPUT | |||
| A | B | C | Sum = A ⊕ B ⊕ C | Carry = A.B + (A ⊕ B) C |
| 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 | 0 |
| 0 | 1 | 0 | 1 | 0 |
| 0 | 1 | 1 | 0 | 1 |
| 1 | 0 | 0 | 1 | 0 |
| 1 | 0 | 1 | 0 | 1 |
| 1 | 1 | 0 | 0 | 1 |
| 1 | 1 | 1 | 1 | 1 |
BASIC GATE
OUTPUT
FULL ADDER USING NAND
FULL ADDER USING NOR
Half Subtractor:
Subtracting a single-bit binary value B from another A (i.e. A -B ) produces
a difference bit D and a borrow out bit B-out. This operation is called half subtraction and the
circuit to realize it is called a half subtractor.
| TURTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | D = A ⊕ B | B = AB |
| 0 | 0 | 0 | 0 |
| 0 | 1 | 1 | 1 |
| 1 | 0 | 1 | 0 |
| 1 | 1 | 0 | 0 |
BASIC GATE
OUTPUT
HALF SUBTRACTOR USING NAND
HALF SUBTRACTOR USING NOR
Full Subtractor:
Subtracting two single-bit binary values, B, Cin from a single-bit value A
produces a difference bit D and a borrow out Br bit. This is called full subtraction.
| TURTH TABLE | ||||
|---|---|---|---|---|
| INPUT | OUTPUT | |||
| A | B | C | D =A ⊕ B ⊕ C | B = AB + BC + AC |
| 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 | 1 |
| 0 | 1 | 0 | 1 | 1 |
| 0 | 1 | 1 | 0 | 1 |
| 1 | 0 | 0 | 1 | 0 |
| 1 | 0 | 1 | 0 | 0 |
| 1 | 1 | 0 | 0 | 0 |
| 1 | 1 | 1 | 1 | 1 |
BASIC GATE
OUTPUT
FULL SUBTRACTOR USING NAND
FULL SUBTRACTOR USING NOR
I like looking through an article that will make men and women think. Also, many thanks for allowing for me to comment!
I discovered your Adder & Subtractor ( Half Adder | Full Adder & Half Subtractor | Full Subtractor ) – AHIRLABS page and noticed you could have a lot more traffic. I have found that the key to running a website is making sure the visitors you are getting are interested in your subject matter. We can send you targeted traffic and we let you try it for free. Get over 1,000 targeted visitors per day to your website.
Simply wish to say your article is as astounding. The clarity on your submit is simply cool and i can assume you’re a professional on this subject.
Fine along with your permission let me to grab your feed to keep up to date with drawing close post.
Thanks one million and please continue the enjoyable work.
I don’t know whether it’s just me or if everyone else experiencing issues with your site. It seems like some of the text within your posts are running off the screen. Can somebody else please comment and let me know if this is happening to them too? This could be a issue with my internet browser because I’ve had this happen before. Thanks
It works really well for me
You don’t require more than 9 nand or 9 nor Gates to implement a full adder or full subtractor..
Which software you had use for draw these diagrams?
logisim
Good Explanation
You are in my bookmarks now!
Thanks Sir
Certainly I like your website, however you have to check the spelling on several of your posts. Many of them are rife with spelling problems and I find it very silly to inform you. Nevertheless I’ll definitely come again again!
Thanx for a very interesting web site. What else could I get that type of information written in such a perfect means? I’ve a mission that I am simply now operating on, and I have been on the look out for such information.
The full substractor truth table is wrong. When
Thanks For Telling Us.
A great post without any doubt.