How do the registers help in instruction execution, Computer Engineering

Assignment Help:

Q. How do the registers help in instruction execution?

We will discuss this in following steps:

Step 1:

First step of instruction execution is to fetch instruction which is to be executed. To do so we need:

  • Address of 'instruction to be fetched'. Generally Program counter (PC) register stores this information.
  • Now this address is converted to physical machine address and put on address bus with help of a buffer register sometimes termed as Memory Address Register (MAR).
  • This coupled with a request from CU for reading, fetches instruction on the data bus and transfers instruction to Instruction Register (IR).
  • On the completion of fetch PC is incremented to point to subsequent instruction.

In Step 2:

  • The IR is decoded.Let's presume that Instruction Register comprises an instruction ADD Memory location B with general purpose register R1 and store result in R1 then CU will first instruct to:
  • Get data of memory location B to buffer register for data (DR) employing buffer address register (MAR) by issuing Memory read operation.
  • This data can be stored in a general purpose register if so required let's say R2
  • Now ALU will perform addition of R1 and R2 under the command of CU and the result will be put back in R1. The status of ALUoperation for illustration result in nonzero/zero, overflow/no overflow etc. is recorded in status register.
  • In the same way the other instructions are fetched and executed by using ALU and register under control of the CU.

So for explaining instruction execution we should explain the registers layout and micro-operations, ALU design and lately the control unit organization.


Related Discussions:- How do the registers help in instruction execution

What is message passing libraries, Q. What is Message Passing Libraries? ...

Q. What is Message Passing Libraries? In this part we will consider about message passing libraries. Traditionally a range of message passing libraries have been available ever

What are pooled tables, Normal 0 false false false EN-I...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

The long and short date option , In MS Access, the long and short date opti...

In MS Access, the long and short date option does not show 4 digit years. How do I achieve the mm/dd/yyyy format? Ans) In the date field properties of the table, form, or prop

Define the vbscript basics, VBScript is an easy and powerful to learn tool ...

VBScript is an easy and powerful to learn tool which can be used to add interaction to your Web pages. Web browser receives scripts along with rest of the Web document. Browser par

Define the resolution of externally defined symbols, Resolution of external...

Resolution of externally defined symbols is performed by Ans. By Linker resolution of externally defined symbols is performed.

What is compact disk rom, Q. What is Compact Disk ROM? Both audio CD an...

Q. What is Compact Disk ROM? Both audio CD and CD-ROM (compact disk read-only memory) share similar technology. Main difference is that CD-ROM players are more rugged and have

What does a lock object involve, What does a lock object involve? The t...

What does a lock object involve? The tables. The lock argument.

Binary floating-point number range, Q. Binary floating-point number range? ...

Q. Binary floating-point number range? Smallest Negative number   Maximum mantissa and maximum exponent     =    - (1 -2 -24 ) × 2 127   Largest negative number

Solution of multi-layer ann with sigmoid units, Solution of multi-layer ann...

Solution of multi-layer ann with sigmoid units: Assume here that we input the values 10, 30, 20 with the three input units and from top to bottom. So after then the weighted s

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