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

Depth-first search is different from breadth-first search, Depth-first sear...

Depth-first search is different from Breadth-first search in the following ways: A depth search traversal method goes to the deepest level of the tree first and then works up w

Explain about fundamental nature of a computer, Q. Explain about fundamenta...

Q. Explain about fundamental nature of a Computer? The fundamental nature of a Computer is as an information transformer. So a computer should be able to take input and process

Explain the register transfer language, Explain the Register transfer langu...

Explain the Register transfer language Register transfer language means there must be data flow between two registers and logic is in between them for end registers data must f

C++, Write a program to find the area under the curve y = f(x) between x = ...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

What is the difference among declaration and definition, The declaration te...

The declaration tells the compiler that at some later point we plan to show the definition of this declaration. E.g.: void stars () //function declaration The definition con

Describe about remote-load latency problem, Q. Describe about Remote-load L...

Q. Describe about Remote-load Latency Problem? When one processor requires some remote loading of data from other nodes then processor has to wait for these two remote load ope

Determine the analog output voltage of 6-bit DAC, Determine the analog outp...

Determine the analog output voltage of 6-bit DAC (R-2R ladder network) with Vref as 5V when the digital input is 011100. Ans. The analog output for 6-bit R-2R DAC ladder network

Rule in a single direction - equivalences rules, Rule in a single direction...

Rule in a single direction - equivalences rules: Hence there the power to replace  sub expressions always allows use to prove theorems with equivalences: as given in the above

Find out how many words can be formed from daughter, Find out how many word...

Find out how many words can be formed out of the letters of the word DAUGHTER such that (i)  The vowels are all time together. (ii)  The vowels occupy even places.   Ans:

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