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

Sql injection, SQL Injection includes entering SQL code into web forms, eg....

SQL Injection includes entering SQL code into web forms, eg. login fields, or into the browser address field, to access and manipulate the database across the site, application or

Find out the correction to be applied in decimal adder, The correction to b...

The correction to be applied in decimal adder to the generated sum is ? Ans. 00110 is the generated sum when the correction to be applied in decimal adder. While the 4 bit su

Why is xml such an important development, It takes away two constraints whi...

It takes away two constraints which were holding back Web developments: 1. Dependence on a one, inflexible document type (HTML) which was being much abused for tasks it was neve

Explain the boolean equations for logic circuits, Explain The Boolean Equat...

Explain The Boolean Equations for Logic Circuits? A Boolean equation is the mathematical representation of a logic circuit using standard Boolean terms. All the logic gates (AND,

QUELING SYTEM , SHOW THAT AVERAGE NUMBER OF UNIT IN A (M/M/1) QUELING SYTEM...

SHOW THAT AVERAGE NUMBER OF UNIT IN A (M/M/1) QUELING SYTEM IS EQUAL TO P/(1-p). NOTE:P=ROW

Give brief description about arithmetic processing unit, Give brief descrip...

Give brief description about arithmetic processing unit To execute the arithmetic operations there is a separate section known as arithmetic processing unit in CPU. The arithme

Btree, What should the size of ''t'' in btree be depending on the hard disk...

What should the size of ''t'' in btree be depending on the hard disk size

Determine the benefits of developing prototype, Determine the benefits of d...

Determine the benefits of developing prototype According to SOMM [96] benefits of developing prototype are as following:  1.  Communication gap between clients and software

Explain the do while loops, Explain The do while loops The do while loo...

Explain The do while loops The do while loops is similar, but the test occurs after the loop body is executed. This ensures that the loop body is run at least once.

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