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1. basis concepts

  • Micro-operations: We have already seen that the programs are executed as a sequence of instructions, each instruction consists of a series of steps that make up the instruction cycle fetch, decode, etc. Each of these steps are, in turn, made up of a smaller series of steps called micro-operations.
  • Micro-operation execution: Each step of the instruction cycle can be decomposed into micro-operation primitives that are performed in a precise time sequence. Each micro-operation is initiated and controlled based on the use of control signals / lines coming from the control unit.

- Controller the data to move from one register to another

- Controller the activate specific ALU functions

  • Micro-instruction: Each instruction of the processor is translated into a sequence of lower-level micro-instructions. The process of translation and execution are to as microprogramming
  • Microprogramming: The concept of microprogramming was developed by Maurice Wilkes in 1951, using diode matrices for the memory element. A microprogram consist of a sequence of micro-instructions in a microprogramming.
  • Microprogrammed Control Unit is a relatively logic circuit that is capable of sequencing through micro-instructions and generating control signal to execute each micro-instruction.
  • Control Unit: The control Unit is an important portion of the processor.

The control unit issues control signals external to the processor to cause data echange with memory and I/O unit. The control Unit issues also control signals internal to the processor to move data between registres, to perform the ALU and other internal operations in processor. In a hardwired control unit, the control signals are generated by a micro-instruction are used to controller register transfers and ALU operations. Control Unit design is then the collection and the implementation of all of the needed control signals for the micro-instruction executions.

2. control unit design approaches

How can we use the concept of microprogramming to implement a Control Unit ? There are two approaches of Control Unit Design and implementation:

- Microprogrammed implementation

- Hardwired logic implementation

The figure 7.2 illustrated the control unit inputs. Two techniques have been used to implemente the CU. In a hardwired implementation, the control unit is essentially considered as a logic circuit. Its input logic signals are transformed into the set of ouput logic signals, which are the control signals. The approach of microprogrammed implementation is studied in this section.

Figure 7.2 Control unit with decoded inputs

2.1 approach of microprogrammed control unit

Principe:

- The control signal values for each microoperation are stored in a memory.

- Reading the contents of the control store in a prescribed order is equivalent to sequencing through the microoperations

- Since the “microprogram” of microoperations and their control signal values are stored in memory, this is a microprogrammed unit.

Remarks:

  • Are more systematic with a well defined format?
  • Can be easily modified during the design process?
  • Require more components to implement
  • Tend to be slower than hardwired units (due to having to perform memory read operations)

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Good
with the given example MOV BX,AX describe the sequence that will be followed using instruction state diagram
Gireesh Reply

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Source:  OpenStax, Computer architecture. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10761/1.1
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