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

Pipeline processing-parallel computer architecture , Pipeline Processing ...

Pipeline Processing Pipelining is a process to realize, overlapped parallelism in the proposed answer of a problem, on a digital computer in an economical way. To understand th

Explain busy hour call attempts in telephone traffic, With reference to tel...

With reference to telephone traffic, explain the terms BHCA. BHCA: The number of call attempts in the busy hour is termed as busy hour call attempts (BHCA) that is an importa

What are the necessary elements of an e-banking site, What are the necessar...

What are the necessary elements of an e-banking site? E-banking systems rely upon a number of common elements or processes. The given list comprises many of the potential elem

Characteristics of input- output channels, Q. Characteristics of input- out...

Q. Characteristics of input- output channels? The I/O channel represents an extension of DMA concept. An I/O channel has ability to execute I/O instructions that gives complete

Explain frequency-division multiplexing, Q. Explain Frequency-division mult...

Q. Explain Frequency-division multiplexing? Frequency-division multiplexing (FDM) is a technique for data transmission widely used in telephone, radio, and cable TV systems in

Calculate a table of responses to all boolean inputs, 1.  The network shown...

1.  The network shown in figure 2 uses neurons with:             (a) Unipolar Binary;             (b) Bipolar Binary. Calculate a table of responses to all four possi

Expression for boolean function in standard POSform, Write the expression f...

Write the expression for Boolean function for F (A, B, C) = ∑m (1,4,5,6,7) in standard POS form.                                   Ans: f (A,B,C )= ΣM (1,4,5,6,7) in standard POS

Continuous or discrete - artificial intelligence, Continuous or Discrete - ...

Continuous or Discrete - artificial intelligence: The behaviour of the coming data in from the environment will change how the agent should be programming. In particular, the

Full form of www, What do you understand by WWW WWW: The World Wide ...

What do you understand by WWW WWW: The World Wide is an architectural framework for accessing linked documents increase out over thousands of machines all over the world. It

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