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

Problems for decision tree learning, A ppropriate Problems for Decision Tr...

A ppropriate Problems for Decision Tree Learning - Artificial intelligence It is a expert job in AI to select accurately the right learning representation for a particular lea

Program, Write a program to find the area under the curve y = f(x) between ...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

What are priority queues, What are priority Queues? There are many queu...

What are priority Queues? There are many queues in which we can insert items or delete items from any of the position based on some property. Now, those queues based on the pro

Information technology or information system, Information Technology or Inf...

Information Technology or Information System Before going further we need to clarify what we mean by the term information system. It is easy to confuse terminology as many tex

Specifying optimisation criteria of describe function, Specifying Optimisat...

Specifying Optimisation Criteria Specify values to be minimized, maximized or optimized. You can understand it as way you normalize data in database. For instance, you should

Multiple instruction and single data stream (misd), Multiple Instruction an...

Multiple Instruction and Single Data stream (MISD) In this association, multiple processing elements are structured under the control of multiple control units. Each control un

Explain in details the various standard i/o interfaces, Explain in details ...

Explain in details the various standard I/O interfaces. The various standard I/O interfaces are:  1. The Peripheral component interconnect(PCI) bus is a standard that suppor

Explain the role of a bus arbiter in a multiprocessor, Explain the role of ...

Explain the role of a bus arbiter in a multiprocessor configuration. Bus arbiter: Which functions to resolve priority between bus masters and allows only one device at a time t

How do you traverse a btree in backward in-order, Put the node in the right...

Put the node in the right subtree Then, Put the root  Put the node in the left subtree

Software characteristics, Software Characteristics: Software is en...

Software Characteristics: Software is engineered and developed. Software can't "wear-out". Most of the software continues to be routine built. The term in

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