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

System analysis and design, write an algorithm on railway reservation ticke...

write an algorithm on railway reservation ticket window

Define bandwidth, Define Bandwidth? When transferring blocks of data, i...

Define Bandwidth? When transferring blocks of data, it is of interest to know how much time is required to transfer an entire block, as blocks can be variable in size it is use

Show the internet protocols, A communication protocol is an agreement which...

A communication protocol is an agreement which specifies a common language two computers use to exchange messages. For instance, a protocol specifies exact format and meaning of ev

Implementation of 3 line to 8 line decoder, Implement the following functio...

Implement the following function using a 3 line to 8 line decoder. S (A,B,C) =   ∑ m(1,2,4,7) C (A,B,C) =  ∑ m ( 3,5,6,7)         Ans. Given function S (A,B,C) = m (1,2,4,7)

EME, How can i made Carnot engine

How can i made Carnot engine

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.

Assignment for statical natural language processing, Hi I study master of ...

Hi I study master of computer science I have assignment for subject statical natural language processing . I need solved due date on 6 May2014 at 11 pm Australia time I need yo

Differentiate the latch and flip-flop, Differentiate the latch and flip-flo...

Differentiate the latch and flip-flop? The major difference between latch and FF is which latches is level sensitive whereas FF is edge sensitive. They both need the use of clo

The voltage of telephone given by telephone companies, Telephone companies ...

Telephone companies normally provide a voltage of to power telephones? Telephone companies usually give a voltage of to power telephones -48 volts DC.

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