Solve Digital Logic Homework: Simplify w/ K-map, Sum of Prods & NAND Gates

In summary: NAND gates, we first need to convert it into a sum of products form, which is a series of AND gates followed by a NAND gate. The sum of products form of our function is:f(w, x, y, z) = (y'z' + x'z)'Next, we will need to use De Morgan's laws to convert the expression into a product of sums form, which is a series of OR gates followed by a NAND gate. The product of sums form of our function is:f(w, x, y, z) = (y' + z)(x' + z)'Finally, we can implement this function using NAND gates as shown in the circuit diagram below:In summary, to simplify
  • #1
TimTimBoBim
1
0

Homework Statement



Using k-map simplify the boolean function:

f(w, x, y, z) = [tex]\prod[/tex](1, 3, 4, 5, 7, 11, 12, 13, 15)

into sum of products form

product of sums form

implement using nand gates

Homework Equations




The Attempt at a Solution



I have the k-map, I understand that part. What I don't understand is how to extract the boolean function from the k-map. The NAND gates part I'm clueless on.

Notes
I'm studying for a test and this is a random example problem. I would thoroughly appreciate a walk-through.

Also, for a different question, how do I extract a boolean function from a circuit drawing? Meaning, there are 4 XOR's, leading to 2 AND's, leading to 1 AND.How do I create a boolean function by looking at that drawing?

Thank you.
 
Physics news on Phys.org
  • #2


Hi there,

I would be happy to walk you through the process of simplifying a boolean function using a k-map and implementing it with NAND gates. Let's start with the given boolean function:

f(w, x, y, z) = \prod(1, 3, 4, 5, 7, 11, 12, 13, 15)

To simplify this function, we will use a k-map. First, we need to arrange the minterms in the k-map according to their binary representation. Since we have 4 variables (w, x, y, z), we will need a 4-variable k-map. The k-map will look like this:

| 00 | 01 | 11 | 10 |
|----|----|----|----|
| 0 | 0 | 1 | 0 |
| 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 0 |
| 0 | 0 | 1 | 1 |

Next, we will group the minterms based on their adjacent 1's in the k-map. The groups should be as large as possible and should be in the shape of squares or rectangles. In this case, we have two groups: one with 4 minterms and one with 2 minterms. The groups are shown in the k-map below:

| 00 | 01 | 11 | 10 |
|----|----|----|----|
| 0 | 0 | 1 | 0 |
| 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 0 |
| 0 | 0 | 1 | 1 |

Next, we will write the simplified boolean function by combining the variables that remain constant within each group. For the first group, the variable y remains constant at 0, so we can write it as y' (y prime). For the second group, the variable x remains constant at 0, so we can write it as x'. The final simplified boolean function is:

f(w, x, y, z) = y'z' + x'z

To implement this function with
 
  • #3




To solve this digital logic homework, we will first need to understand how to use a k-map to simplify a boolean function. The k-map is a graphical method that helps us to identify patterns in the truth table of a boolean function and simplify it using boolean algebra. In this case, we have a boolean function with four variables, w, x, y, and z. The k-map will have 16 cells, each representing a possible combination of the four variables.

To extract the boolean function from the k-map, we will first group the cells that have a value of 1 together. These groups should be as large as possible and can be in the form of squares, rectangles, or adjacent cells. Each group will represent a term in the boolean function. For example, in the k-map given, we can group cells 1, 3, 4, 5, 7, 11, 12, 13, and 15 together to form a rectangle. This group represents the term w'x'yz' in the boolean function.

After identifying all the groups, we can write the simplified boolean function in sum of products form. This means that we will take the complement of the variables in each group and multiply them together. In this case, our simplified boolean function would be:

f(w, x, y, z) = w'x'yz' + w'x'yz + w'x'y'z' + w'x'y'z + wxy'z' + wxy'z + wxyz' + wxyz + wx'yz'

To implement this function using NAND gates, we can use DeMorgan's theorem to convert the sum of products form into a product of sums form. This means that we will take the complement of the entire simplified boolean function and then use NAND gates to implement it. The simplified boolean function in product of sums form would be:

f(w, x, y, z) = (w + x + y' + z)(w + x + y + z')(w + x' + y' + z')(w + x' + y' + z)(w + x' + y + z')(w + x' + y + z)(w + x + y' + z')(w + x + y' + z)(w + x + y + z)

To implement this using NAND gates, we will first
 

1. What is a K-map and how is it used to simplify digital logic problems?

A Karnaugh map, also known as K-map, is a graphical tool used to simplify Boolean algebra expressions. It consists of a grid with cells that represent all the possible combinations of input variables. By grouping together adjacent cells with the same output value, we can reduce the number of terms in a Boolean expression and simplify the digital logic problem.

2. What is the Sum of Products (SOP) form and how is it used in digital logic?

The Sum of Products (SOP) form is a way of representing Boolean expressions using the logical OR operation. It is formed by taking the product of all the input variables that result in the desired output and then summing them together. In digital logic, the SOP form is used as a simplified and more efficient way of implementing logic functions using AND, OR, and NOT gates.

3. What are NAND gates and how are they used in digital logic?

NAND gates, short for Not AND gates, are one of the basic building blocks of digital logic circuits. They perform the logical operation of negation on the inputs, meaning that the output will be the opposite of the AND operation on the inputs. NAND gates are commonly used in digital logic to implement various Boolean functions and can be used to replace other logic gates such as AND, OR, and NOT gates.

4. How do I approach solving a digital logic homework problem using K-map and SOP form?

The first step is to create a truth table for the given inputs and outputs. Then, using the truth table, you can create a K-map and group together adjacent cells with the same output value. From there, you can write the simplified expression in SOP form. Finally, you can implement the expression using NAND gates, if required.

5. Can I use K-map and SOP form to solve any digital logic problem?

Yes, K-map and SOP form can be used to solve any digital logic problem that involves simplifying Boolean expressions. However, for more complex problems, other techniques such as Quine-McCluskey method may be more efficient. It is important to have a good understanding of Boolean algebra and digital logic principles to effectively use K-map and SOP form for solving problems.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
4
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
14
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
9
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
14
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
6
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
4
Views
3K
Back
Top