opcode and operands, Basic Computer Science

Assignment Help:

Opcode and operands:

Let us further assume that our computer can process only two-digit decimal numbers, i.e. there can be a maximum of two operands each of a maximum of two digits. Thus the computer can add or subtract numbers containing a maximum of two digits. A simple instruction can thus be written as a combination of an opcode and its associated operands. Opcode is denoted by its unique binary code. The operands are decimal digits and therefore also need to be converted to binary code system to pass them as operands to the processor. Suppose BCD code is used to represent the operands. Then following are examples of some valid instructions on the processor:

 

791_opecode.png

In the first instruction, the first three bits represent the opcode and the remaining sixteen bits represent the two operands each a two digit decimal number expressed using BCD code. The opcode for addition  as described in the table is 000 and the BCD codes for 9,3,2 and 5 are 1001, 0011, 0010 and 0101 respectively. Thus the instruction 0001001001100100101 represents 93 + 25. Similarly, in the second instruction, first three bits represent the opcode and the  remaining eight bits specify the operand to perform the operation. However, this is the case of a very simple hypothetical computer. Real world processors are much more complex and capable of performing more than 500 machine instructions. Further they can  take their operands in a number ways: directly, from registers, from memory etc. Moreover, modern processors can perform calculations on large numbers. Thus an instruction in a modern CPU could easily comprise  more than 50 bits.      


Related Discussions:- opcode and operands

What are the features of microprocessor ?, Previously two sections the fund...

Previously two sections the fundamentals of the workings and architecture of the central processing unit has been explained. There has been a common look at easy processor architec

Algorithms and pseudocodes.., how do you write the algorithm and the pseudo...

how do you write the algorithm and the pseudo code for cramer''s rule in visual basic.

Internet searching algorithm, Internet searching algorithm: Searching: Wh...

Internet searching algorithm: Searching: When a user enters a query into a search engine, the engine examines its index and provides a listing of best-matching web pages accordin

Microwave transmission, Microwave Transmission: Using space as transmi...

Microwave Transmission: Using space as transmission medium, microwave emanates from an origination point on earth, such as telephone exchange, where many individual messages h

On-line and realtime systems, On-line and Realtime Systems An on-line s...

On-line and Realtime Systems An on-line system means that input and output devices are directly connected to the CPU irrespective of geographical location. Thus the user can di

Protocol, what protocol is used by DNS name server

what protocol is used by DNS name server

Explain particle collision in detail, Question 1 Name the different types ...

Question 1 Name the different types of emitters and explain them in brief Question 2 List and explain the Particle Attributes Question 3 Explain Particle Collision

Boolean expression, Problem 1. Obtain the truth table and a Boolean exp...

Problem 1. Obtain the truth table and a Boolean expression for the following conditions: x is 0 if any two of the three variables are 1. x is 1 for all other conditions.

Algorithm and flowchart, Write an alogorithm to calculate the right angled ...

Write an alogorithm to calculate the right angled triangle

Assignment, write an essay explaining the following: 1.Storage aspects a. D...

write an essay explaining the following: 1.Storage aspects a. Disk formatting, b.Disk boot block ,c.Bad block removal, d.Compensation.

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