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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

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
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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