Describe program control instructions, Computer Engineering

Assignment Help:

Q. Describe Program Control Instructions?

These instructions specify conditions for altering the sequence of program execution or we can say in other words that the content of PC (program counter) register.  PC points to memory location which holds the subsequent instruction to be executed. The alteration in value of PC as a result of execution of control instruction such as BRANCH or JUMP causes a break in sequential execution of instructions. The most common control instructions are as following:

JUMP and BRANCH may be unconditional or conditional. JUMP is an unconditional branch used to implement simple loops. JNE jump not equal is conditional branch instruction. The conditional branch instructions like BRP X and BRN X causes a branch to memory location X if the result of most recent operation is positive or negative correspondingly. If the condition is true PC is loaded with branch address X and next instruction is taken from X otherwise PC is not changed and the subsequent instruction is taken from location pointed by PC. Figure below displays an unconditional branch instruction and a conditional branch instruction if content of AC is zero.

MBR←0; Assign 0 to MBR register

X←2001; Assume X to be an address location 2001

READ X; Read a value from memory location 2001 into AC

BRZ 1007; Branch to location 1007 if AC is zero (Conditional branch on zero)

ADD MBR; add the content of MBR to AC and store result to AC

TRAS MBR; Transfer the contents of AC to MBR 

INC X; Increment X to point to next location 

JUMP 1001;Loop back for further processing.

Related Discussions:- Describe program control instructions

Illustrate the term extranet, Illustrate the term Extranet? Extranet:...

Illustrate the term Extranet? Extranet: Extranet is Extension of an Intranet that makes thelatter accessible to outside companies or individuals with or without an intran

Describe generic framework for electronic commerce, Describe generic framew...

Describe generic framework for electronic commerce Generic Framework for electronic commerce contains the Applications of EC   (like as banking, shopping in online stores and m

Physics, derive an expression for vandar wall equation of state?

derive an expression for vandar wall equation of state?

Explain structured and modular programming, Structured and Modular programm...

Structured and Modular programming. Structured programming means the collection of principles and practices that are directed toward developing correct programs which are simpl

Line of code of assembly language, In how many ways line of code of assembl...

In how many ways line of code of assembly language can be divided? A line of code of an assembly language program can be divided in three columns called as fields. The fields d

Selecting integerated learning experiences, Q. Selecting integerated learni...

Q. Selecting integerated learning experiences? It is important that we select appropriate experiences for children, more so those that are from the child's world and emerge fro

Script in multi user mode, What Component of LoadRunner would you use to pl...

What Component of LoadRunner would you use to play Back the script in multi user mode? Ans) The Controller component is used to playback the script in multi-user mode. This is c

Define throughput, Define throughput?  Throughput in CPU scheduling is ...

Define throughput?  Throughput in CPU scheduling is the number of processes that are completed per unit time. For long processes, this rate might be one process per hour; for s

What is link destruction, What is link destruction? Link destruction is...

What is link destruction? Link destruction is inverse of link creation. When a link is destroyed makes sure the associated objects accessible by other handles or intentionally

Explain the working principle of hard disk, Question : a) Hard disk is ...

Question : a) Hard disk is an important component of a computer. What type of memory is it? b) With the help of a diagram describe its features. c) Explain its working pr

Write Your Message!

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