The Quine-McCluskey Method, also known as the Tabulation Method is a specific step-by-step method that is ensured to generate a simplified standard-form expression for a function. Ronwaldo A. Collado Diosdado Y. Tejoso Jr. CMSC 130 Logistic Design and Digital Computer Circuits Second Semester, A. Y. 2012-3013
ii Quine-McCluskey Simulator
iii Table of Contents About the Quine-McCluskey Method...iv About the Quine-McCluskey Simulator...v Your First Glance to the Simulator...1 The Simulator Window...2 The Variable Menu...3 The Input/Output Menu...4 The Input Area...5 The Quine-McCluskey Simulation...7 Renaming Your Function...8 Adding another Function...9
iv Quine-McCluskey Simulator About the Quine-McCluskey Method Karnaugh maps are very effective for the minimization of expressions with up to 5 or 6 inputs. However, Karnaugh maps are difficult to use with a large number of inputs, since it is hard to find groups of adjacent squares. Also, according to Amaral (2003), Karnaugh maps depend on our ability to visually identify prime implicants and select a set of prime implicants that cover all minterms. They do not provide a direct algorithm to be implemented in a computer. The Quine-McCluskey method is an exact algorithm which finds a minimum-cost sum-of-products implementation of a Boolean function. It has four main steps (Nowick, 2013): 1. Generate Prime Implicants 2. Construct Prime Implicant Table 3. Reduce Prime Implicant Table a. Remove Essential Prime Implicants b. Row Dominance c. Column Dominance 4. Solve Prime Implicant Table
v About the Quine-McCluskey Simulator The Quine-McCluskey Simulator is an Executable Jar File that performs the Quine-McCluskey Method. It only needs the designation numbers of the minterms where a Boolean function evaluates to 1. Also, this simulator enables the user to manipulate: 1. the variable usage; and 2. the input and output types. Moreover, the simulator shows the complete process of the Quine-McCluskey Method. It enables the user to add another Boolean function to work on.
vi Quine-McCluskey Simulator
1 Your First Glance to the Simulator Y ou must open the Executable Jar File in order to use the Quine- McCluskey Simulator. This will be your first glance to the simulator: After entering your name (e. g. User 1):
2 Quine-McCluskey Simulator The Simulator Window Title Bar: Notice that the name entered is viewed Variable Menu: The user can manipulate the variable usage. (More details later) Input Area Output Area Input/Output Menu: The user can manipulate the input and output type. (More details later)
3 The Variable Menu 1 2 3 4 1 Variable Count: It indicates the number of variables to be used. If checked, the number of variables to be used should be placed in the textarea (maximum number of terms is 20). If remained unchecked, the number of variables to be used will depend on the largest designation number in the input area (where the minterms or maxterms should be listed). 2 Default: The default variables are the letters of the alphabet starting from a. It is arranged sequentially (i. e. a, b, c, and so on.). 3 Random: The variables to be used will be selected randomly from the letters of the English alphabet. (i. e. It will not be arranged alphabetically) 4 4 Sequential: It is used when Random option was selected. It indicates that the variables to be used should be arranged alphabetically.
The Input/Output Menu 1 2 1 Input Type Options: The default input type is in minterms (designation number of the terms where the function evaluates to 1). If the user chooses that the input type to be in maxterms, he/she should input the designation number of the terms where the function evaluates to 0. 2 Output Type Options: If the input type is in minterms the default output type is in sum of products form (i. e., ab + cd + e). When the input type is in maxterms, the default output type is in product of sums form (i. e., (a + b)(c + d)(e)). The user can change the output type by first marking the checkbox, then selecting the output type he/she desires.
5 The Input Area 1 2 1 Input Text Area: The input should be written in this text box. The label already explains the format to be used. Note that each designation number of the terms must be separated by spaces. 2 No Input Terms: This checkbox is used to declare that there are no input minterms nor maxterms in the function. 2 OK Button: When clicked, the Quine-McCluskey Simulation will begin. (You may not click this button by pressing Enter ). 3
6 Quine-McCluskey Simulator The Quine-McCluskey Simulation Now that you are familiar to the environment of the Quine- McCluskey Simulator, let us try an example: Obtain the simplified expression of a Boolean function containing the minterms evaluating to 1 at: 6, 9, 13, 18, 19, 25, 27, 29, 41, 45, 57, and 61. Step 1: Type in the designated number of minterms evaluating to 1 in the input text area.
7 Step 2: Click OK or press Enter. Solution Summary: Displays the given function and the simplified expression/s obtained using the Quine- McCluskey Method Closes the current Tab You can rename the tab label of the function Solution Box: Displays the complete solution using the Quine- McCluskey Method* Navigation Buttons You can navigate between tables or charts using these buttons * In this example, you can see, four grouping tables, the prime implicants table, the prime implicants chart, removal of essential implicants, Petrick s method, and the possible combinations (there are two possible simplified expressions in this example).
8 Quine-McCluskey Simulator Renaming Your Function As viewed in the previous page, you can rename the tab label of your current function. After clicking the Rename Function button: In this case, we can used Example 1 :
9 Adding another Function As stated at the About the Quine-McCluskey Simulator, you can work on another Boolean function. In the Menu (located below the title bar), there is an option on adding another Boolean function. After selecting Add a Boolean Function, the simulator window will look like: Notice that the previous function is already viewed at the output area. Now, you can work on another function and view your previous ones!