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

Explain about com add-ins, COM add-ins are software program's which are inc...

COM add-ins are software program's which are included into an application and they add already built in features to an existing application. They have general architecture across m

Explain about fat - inode, Q. Explain about FAT - Inode? Today modern P...

Q. Explain about FAT - Inode? Today modern PC comprises total capacity of nearly 40GB for storage of program and data Due to this huge capacity in place of having just one oper

Define the resolution of externally defined symbols, Resolution of external...

Resolution of externally defined symbols is performed by Ans. By Linker resolution of externally defined symbols is performed.

Host computer-array processing, Host Computer:  An array processor may be a...

Host Computer:  An array processor may be attached to a host computer by the control unit. The reason of the host computer is to broadcast a sequence of vector instructions by CU t

How many types of stages include in process of data mining, How many types ...

How many types of stages include in process of data mining? The process of data mining comprised three stages as given below: a) The initial exploration b) Model buildin

Determine about selective set- logic micro operations, Selective set Th...

Selective set The selective-set operation sets to 1 bits in register A where there can corresponding 1's  in  register  B.  It  does  not  affect  bit  positions  which  have

Determine the use of loop instruction, Q. Determine the use of LOOP instruc...

Q. Determine the use of LOOP instruction? Program: This program prints the alphabets (A-Z) ; Register used: AX, CX, DX CODE SEGMENT ASSUME: CS: CODE.     MAINP:

What is computer communications networks, Q. What is Computer communication...

Q. What is Computer communications networks? Computer communications networks are the outcome of a combination of computers and telecommunication products. An interconnected gr

Computer grphics, Advantages of DDa algorithms for line drawimg

Advantages of DDa algorithms for line drawimg

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