Show the steps of execution of instructions, Computer Engineering

Assignment Help:

Q. Show the steps of execution of instructions?

Fetch First Instruction into CPU:

Step 1: Find/calculate the address of first instruction in memory. In this machine illustration next instruction address is contained in PC register. It comprises 1 that is the address of first instruction to be executed. (Figure above part a).

Step 2: Bring binary instruction to IR register. This stage requires:

  • Passing content of PC to Memory Address Registers so that instruction pointed to by PC is obtained i.e. location 1's content is fetched.
  • CPU concerns 'Memory read' operation so brings contents of location pointed by MAR (1 in this particular case) to MBR register.
  • Content of MBR is transferred to IR and PC is incremented to point to subsequent instruction in sequence (2 in this particular case).

Execute the Instruction

Step 3: IR has instruction LOAD A that is decoded like 'Load the content of address A in the accumulator register'.

Step 4: Address of operand which is 13 i.e. A is transferred to MAR register.

Step 5: Content of memory location (signified by MAR which is location 13) is transferred to MBR.

Step 6: Content of MBR is transferred to Accumulator Register.

So the accumulator register is loaded with content of location A that is 5. Now the instruction 1 execution is finished and the subsequent instruction which is 2 (specified by PC) is obtained and PC is incremented to 3. This instruction is ADD B that instructs CPU to add the contents of memory location B to accumulator. On execution of this instruction accumulator will comprise sum of its earlier value which is A and value stored in memory location B.

On execution of instruction at memory location 3 Program Counter becomes 4 and the accumulator results are stored in location C which is 15 and IR still comprises the third instruction. This condition is displayed in figure above part(C).

Please remember that execution of the instructions in above illustration is very simple and needs only data transfer and data processing operations in every instruction. Also these instructions need one memory reference at the time of its execution.


Related Discussions:- Show the steps of execution of instructions

Show the conditional jump in program with example, Q. Show the conditional ...

Q. Show the conditional jump in program? CMP    AX, BX                      ; compare instruction: sets flags JNE     FIX                             ; if not equal do addi

C programming, #write a program to find the area under the curve y=f(x) bet...

#write a program to find the area under the curve y=f(x) between x =a and x=b integrate the area between a and b by c programming

Differentiate between raid 0 and raid 1, Problem 1 a) Give three reaso...

Problem 1 a) Give three reasons why connecting peripherals directly to the system bus are not a good practice. b) Name five categories in which the major functions on requ

What is internet address, Addresses are basically for virtually everything ...

Addresses are basically for virtually everything we do on Internet. The IP in TCP/IP is a mechanism for providing addresses for computers on Internet. Internet addresses have two f

Complexity of sequential search, Specified the average case complexity of s...

Specified the average case complexity of sequential search in an array of unsorted elements of size n if the following conditions hold: a)  Probability of the key to be in the a

Execution of micro-program, The micro-instruction cycle can comprises two b...

The micro-instruction cycle can comprises two basic cycles: the fetch and execute. Here in the fetch cycle address of micro-instruction is produced and this micro-instruction is pu

.master-slave flip flop, JK, SR, D master FF 1)draw block diagram 2) combin...

JK, SR, D master FF 1)draw block diagram 2) combinational circuits using NOR & NAND gate thank you

Explain about asynchronous message passing, Q. Explain about Asynchronous m...

Q. Explain about Asynchronous message passing? In Asynchronous message passing message transmitting and receiving aren't synchronized in space and time. The store and forward

Define the difference between union and structure, Define the difference be...

Define the difference between union and structure The main difference between union and structure is the storage allocation. In Union , for each variable the compiler allocates

Determine the indicator variables in a random forest, Given a dataset with ...

Given a dataset with 1000 rows and 25 predictors labeled x1, x2, ...,x25 to classify into two classes {a, b}. Consider the small random forest with 3 trees and one split in each tr

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