what is Decode or execution cycle?, Basic Computer Science

Assignment Help:
just the once the instruction has been fetched and is accumulated, the next step is to decode the instruction so as to work out what actions should be performed to execute it. This occupies examining the opcode to observe which of the machine codes in the CPU’s instruction set it communicates to, and also verifying which addressing mode needs to be used to get any required data.
Once the opcode is known, the execution cycle can take place. Different actions require to be carried out dependant on the opcode, without two opcodes requiring the same actions to occur. Though, there are usually four groups of different actions that can occur:
• Move of data between the CPU and memory.
• move of data between the CPU and an input or output devices.
• Processing of data, perhaps involving the use of the arithmetic and logic unit.
• A control operation, with the intention of change the sequence of subsequent operations. These can probably be conditional, based on the values stored at that point within the flag register.
For greater ease, and as describing all the possible instructions:
Mnemonic Description
MOV Moves a data value from one location to another
ADD Adds to data values using the ALU, and returns the result to the accumulator
STO Stores the contents of the accumulator in the specified location
END Marks the end of the program in memory

Related Discussions:- what is Decode or execution cycle?

Cp, I NEED FLOW CHART ANT DRAWINGS OF BASIC OPERATIONS OF COMPUTER

I NEED FLOW CHART ANT DRAWINGS OF BASIC OPERATIONS OF COMPUTER

Cryptography, Consider the one-time pad encryption scheme to encrypt a 1-bi...

Consider the one-time pad encryption scheme to encrypt a 1-bit message m, and assume m is chosen with uniform distribution from message space M={0,1}. Let E1 be the event "message

Types of printers, Types of Printers 1. Impact printers The impact...

Types of Printers 1. Impact printers The impact printers produce the image through a mechanism of striking on the stationary. 2. Line Printer This type of printer

College management system project, E-R diagram and details for college mana...

E-R diagram and details for college management system

What is a stateless and and a stateful server, StatefulServer, maintains so...

StatefulServer, maintains some information between requests. Requires smaller messages, since some information is kept between contacts, example: FTP, telnet. Stateless Server req

Probability, Suppose that of 100 computers checked for viruses 30 where inf...

Suppose that of 100 computers checked for viruses 30 where infected and 70 where not. If we select 10 computers at random what is the probability that at most 4 of them are infecte

Distinguish between s-http and ssl, QUESTION (a) Distinguish between S...

QUESTION (a) Distinguish between S-HTTP and SSL (b) What are the three basic security provided by SSL? (c) Discuss the limitations of SSL (d) State the port number us

What is heuristic evaluation, Question 1: (a) How would you describe h...

Question 1: (a) How would you describe human reasoning? (b) Describe the different types of human reasoning? Question 2: (a) What are the computational factors affec

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