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

Loop level-levels of parallel processing, Loop Level At this level, rep...

Loop Level At this level, repeated loop iterations are the applicants for parallel execution. However, data dependencies among subsequent iterations may limit parallel executio

What is double data rate sdram, What is double data rate SDRAM?  Double...

What is double data rate SDRAM?  Double data rates SDRAM are those which can transfer data on both edges of the clock and their bandwidth is fundamentally doubled for long burs

Show the fundamental process of instruction execution, Q. Show the fundamen...

Q. Show the fundamental process of instruction execution? The fundamental process of instruction execution is:  1. Instruction is fetched from memory to CPU registers (calle

What do you understand by work flow automation, What do you understand by w...

What do you understand by work flow automation? Work Flow Automation: Organizations often standardize processes over the organization and encourage users to adopt them. Ev

Define deadlock, Define deadlock? Deadlock is a condition, wherein proc...

Define deadlock? Deadlock is a condition, wherein processes never finish executing and system resources are tied up, preventing another job from beginning. A process requests r

What is accumulator register, Q. What is Accumulator Register? Accumula...

Q. What is Accumulator Register? Accumulator Register (AC):  This register is used to store data temporarily for computation by Arithmetic and logic unit (ALU).  AC generally c

What is application software, What is application software? Give example. ...

What is application software? Give example. Application programs are usually written in a high level programming language, in which the programmer states mathematical or text p

What does a socket having of, The combination of an IP address and a port n...

The combination of an IP address and a port number is known as a socket.

What is base register addressing, Q. What is Base Register Addressing ? ...

Q. What is Base Register Addressing ? An addressing technique in which content of an instruction specifies base register is added to address field or displacement field of the

What is disk access time, Q. What is disk access time? The disk access ...

Q. What is disk access time? The disk access time has two key components: Seek Time: Seek time is the time for disk arm to move heads to the cylinder comprising the desi

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