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

Example of frames format with ethernet, Compute the number of Ethernet fram...

Compute the number of Ethernet frames formed for a data of 64 KB IP packet. Following figure demonstrates the format of the Ethernet frame. Here maximum data into a frame is 15

How can we set the table spaces and extent sizes, How can we set the table ...

How can we set the table spaces and extent sizes? You can state the extent sizes and the table space (physical storage area in the database) in which a transparent table is to

What is the difference between awt and swt, SWT (Standard Widget Toolkit) i...

SWT (Standard Widget Toolkit) is a totally independent Graphical User Interface (GUI) toolkit from IBM. They formed it for the creation of Eclipse Integrated Development Environmen

Concept of pipelining, Describe the concept of pipelining. Ans: Pipeli...

Describe the concept of pipelining. Ans: Pipelining is the means of executing machine instructions concurrently. This is the effective way of organizing concurrent activity in

What is managed code and managed data, What is managed code and managed dat...

What is managed code and managed data? Managed code is code that is written to target the services of the Common Language Runtime. In order to target these services, the code m

Determine about the raster-scan systems, Determine about the raster-scan sy...

Determine about the raster-scan systems Most of the present raster-scan systems contain a separate processor called as display processor. This processor performs graphics func

Explain about transmission media, Q. Explain about Transmission Media? ...

Q. Explain about Transmission Media? These, also known as physical channels, can be either bounded or unbounded. Bounded media, in which signals representing data are confined

Final project, I need help coming with an idea for BSCE final project, whic...

I need help coming with an idea for BSCE final project, which is solvable in about a semester

What are the disadvantages of bespoke software, What are the disadvantages ...

What are the disadvantages of Bespoke Software -  Very dependent on suppliers of the software; if they go out of business there would be little or no support if problems occ

Efficiency of vector processing over scalar processing, Efficiency of Vecto...

Efficiency of Vector Processing over Scalar Processing As we know a serial computer processes single scalar operands at a time. So if we have to process a vector of length 'n'

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