How does the computer execute a program, Computer Engineering

Assignment Help:

Let's attempt to answer a fundamental question: 'How does the Computer execute a Program?' Let's describe this with the help of an example from higher level language domain.

Problem:  Write a program to add two numbers.

A sample C program (Assuming two fixed values of numbers as a = 5 and b = 2)

1.  #include < stdio.h >

2. main ()

3.    {

4.  int a =5, b=2, c;

5. c= a+b;

6. printf ("\n The added value is: % d", c);   

7.           }

Program at line 4 states variables which will be equal to 3 memory locations that are a, b and c.  At line 5 these variables are added along with at line 6 value of c is printed.

However how will these instructions be executed by CPU? First you have to compile this program to convert it to machine language. Though how will the machine instructions look like? Let's suppose a hypothetical instruction set of machines of a size of 16 binary digits (bits) data and instructions. Each one of the instruction of machine comprises two components: (a) Operation code which specifies the operation which is to be performed by instruction and (b) Address of operand in memory on that given operation is to be performed.

Let's further presume that size of operation code is supposed to be of six bits consequently rest 10 bits are for address of operand. Also the memory word size is presumed to be of 16 bits. Figure below shows instruction and data formats for this machine.  To simplify our discussion let's present operation code employing Mnemonics such as ADD, LOAD, STORE and signed decimal values for data and decimal values of operand addresses. 

756_How does the Computer execute a Program.png


Related Discussions:- How does the computer execute a program

What are the elements of analysis model, What are the elements of Analysis ...

What are the elements of Analysis model? i. Data Dictionary ii. Entity Relationship Diagram iii. Data Flow Diagram iv. State Transition Diagram v. Control Specifica

Explain macro definition and call, Explain Macro definition and call. ...

Explain Macro definition and call. Macro: The assembly language programming frequently finds this necessary to repeat certain piece of code several times during the course of

Explain about the links and association, Links and Association Links a...

Links and Association Links and associations are the basic means used for establishing relationships among objects and classes of the system. In the next subsection we will di

Write a bash shell script, Write a BASH/C shell script which takes name of ...

Write a BASH/C shell script which takes name of one or more files as a command line argument, and prints the following information for each file: owner, number of words in the file

Identify which stores most no. of bits in memory store, Which of the memori...

Which of the memories stores the most number of bits ? Ans. 5Mx8 = 5 x 220 x 8 = 40M (max).

Describe the advantages of java servlets over cgi interface, Describe the a...

Describe the advantages of JAVA servlets over CGI interface. The Advantage of Servlets Over "Tradi tional" CGI: Java servlets are extra efficient, easier to utilize more pow

Write c program to read the text book number, With a C program to read the ...

With a C program to read the text book number, title, author and publisher into a structure and print these values. # include # include void main() { struct boo

What are near and far pointers, These days, they're pretty much obsolete; t...

These days, they're pretty much obsolete; they're definitely system-particular. They had to do with 16-bit programming under MS-DOS and perhaps some early on versions of Windows. I

Designing the instruction format, Q. Designing the instruction format is a ...

Q. Designing the instruction format is a complex art? Instruction Length Significance: It's the fundamental issue of the format design. It concludes the richness and flex

What is turnaround time, What is turnaround time? Turnaround time is th...

What is turnaround time? Turnaround time is the interval from the time of submission to the time of completion of a process. It is the sum of the periods spent waiting to get i

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd