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

Discuss in detail about micro computer, Discuss in detail about Micro compu...

Discuss in detail about Micro computer A microcomputer's CPU is a microprocessor. The microcomputer was originated in late 1970s. The first microcomputer was built around 8-bit

Different industries which use this marketing tool, What are the different ...

What are the different industries which use this marketing tool? Ans) Many dissimilar companies can use this tool for developing their business plan but it is often three main

Explain the terms topology used in lans, Explain the terms topology used in...

Explain the terms topology used in LANs. (i) LAN topologies: This network topology is a physical schematic that shows interconnection of the several users. There are four fun

Set up this problem as an lp problem, The Laser Computer Printer Company de...

The Laser Computer Printer Company decides monthly what to produce during the subsequent month. They produce three types of printers, the Laser Rocket, the Alpha Laser, and the La

Explain characteristics of latch and flip-flop, Explain characteristics of ...

Explain characteristics of Latch and Flip-Flop. Latches are level-sensitive and transparent While the clock is high it passes input value to Output While the clock is l

Show the steps of execution of instructions, Q. Show the steps of execution...

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 illust

Weight training calculations - artificial intelligence, Weight Training Cal...

Weight Training Calculations -Artificial intelligence: Because we have more weights in our network than in perceptrons, first we have to introduce the notation: wij to denote t

Identify the number of control lines for 16 to 1 multiplexer, The number of...

The number of control lines for 16 to 1 multiplexer is ? Ans. We have 16 = 2 4 , 4 Select lines are needed.

What is an assembly language, An assembly language is a? Ans. Low level...

An assembly language is a? Ans. Low level programming language is an assembly language.

Design issues, Design issues:  To complete the maximum processor utilizatio...

Design issues:  To complete the maximum processor utilization in a multithreaded architecture, the following design issues have to be addressed: Context Switching time: 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