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

The different storage classes in c, What are the different storage classes ...

What are the different storage classes in C?  Storage classes in C  There are four storage classes in C:  a. Automatic storage class:  b. Register storage class:  c

How to detect a sequence of 1101, Use 4 D-bascules connected in serial all ...

Use 4 D-bascules connected in serial all synchronized with the similar CLK. Then connect all 4 outputs, & 2nd output must reverse, of the D-bascule to an AND logic. The output of t

Define the pulse-triggered (master-slave) flip-flops, Define the Pulse-Trig...

Define the Pulse-Triggered (Master-Slave) Flip-flops? The term pulse-triggered signify that data are entered into the flip-flop on the rising edge of the clock pulse, though th

How a procedure define in assembly, Q. How a Procedure define in Assembly ?...

Q. How a Procedure define in Assembly ? Procedure is defined within source code by placing a directive of form: PROC A procedure is terminated using: ENDP The

Analysis of amdahls law, Q. Analysis of Amdahls law? The conclusions of...

Q. Analysis of Amdahls law? The conclusions of analysis of Amdahl's law are: 1) To optimize performance of parallel computers modified compilers should be developed that sho

When is a memory unit called as ram, When is a memory unit called as RAM? ...

When is a memory unit called as RAM? A memory unit is called as RAM if any location can be accessed for a read or writes operation in some fixed quantity of time that is indepe

Explain about param super computer, Q. Explain about PARAM Super computer? ...

Q. Explain about PARAM Super computer? PARAM is a high-performance, industry standard and scalable computer. It has developed from concepts of distributes scalable computers ma

Calculate register transfer time, Q. Calculate Register Transfer Time? ...

Q. Calculate Register Transfer Time? A clock isn't included explicitly in any statements discussed above. But it is presumed that all transfers take place during clock edge tra

What is test factory, Rational Test Factory is a component-based testing to...

Rational Test Factory is a component-based testing tool that automatically produces TestFactory scripts according to the application's navigational structure. TestFactory is integr

Classify computer systems according to capacity, Classify computer systems ...

Classify computer systems according to capacity. How they are different from computers according to the classification of technology. Provide comparative study also

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