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

Determine flip flop the msi chip is dual edge triggered, The MSI chip 7474 ...

The MSI chip 7474 is ? Ans. MSI chip 7474 is TTL, dual edge triggered D Flip-Flop.

How numbering plan is achieved in modern telephony, How numbering plan is a...

How numbering plan is achieved in modern telephony? Give the structure with example. The objective of numbering plan is to uniquely identify every subscriber connected to a tel

Calculate traffic offered in erlangs in a particular exchang, In a particul...

In a particular exchange during busy hour 1200 calls were offered to a group of trunks, during this time 6 calls were lost. The average call duration being 3 minutes Calculate Traf

Mac address helps in which access control, MAC address helps in (A)  m...

MAC address helps in (A)  multimedia access control. (B)  media access control. (C)  mobile access control. (D) master access point control Ans: MAC addr

Natural and artificial intelligence, Since the term artificial intelligen...

Since the term artificial intelligence was defined in the 1950s, experts have disagreed about the difference between natural and artificial intelligence. Can computers be pro

Layers of distributed system architecture, Q. Layers of Distributed System ...

Q. Layers of Distributed System architecture? Layers of Distributed System architecture are: Presentation Layer is actual user interface. This layer receives input and

Structured analysis and design approach, Q. Structured Analysis and Design ...

Q. Structured Analysis and Design Approach? The objective of structured system analysis and design is to reduce maintenance time as well as effort. Modeling is the act of drawi

State and prove any one of the demorgen''s laws, Q. F(x,y,z) = ∑m (4,6,7,8...

Q. F(x,y,z) = ∑m (4,6,7,8)+ ∑d (2,5,11,12) Using K-Map. Q. State and prove any one of the DeMorgen's Laws. Show that these theorems can be extended up to any number of variabl

Remote-load latency problem, Remote-load Latency Problem:  When one process...

Remote-load Latency Problem:  When one processor requires some remote loading of data by other nodes, then the processor need to wait for these two remote load operations. The long

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