Instruction sets

-
Steps involved in instruction execution in CPU
  • Instructions and data are the information fed to a computer. Instructions are explicit commands that
    • Govern the transfer of information within a computer as well as between the computer and its I/O devices.
    • Specify the arithmetic and logic operations to be performed.
  • A set of instructions that perform a task is called a program usually a program is stored in the memory.
  • The processor then fetches the instructions comprising the program from memory one at a time and perform the desired operations.
  • The computer is under control of stored program, except for the possibility of external interruption from the operator or by I/O devices connected to the machine.
  • The operation of the CPU is determined by the instructions it executes.
  • These instructions are referred to as machine instructions or computer instructions.
  • The collection of different instructions that the CPU can execute is referred to as the CPU‟s instruction set.
  • Each instruction may contain the information required by the CPU for execution.
    • Operation Code: Specifies the operation to be performed. The operation is specified by a binary code known as the operation code or opcode.
    • Source Operand Reference: The operation may involve one or more source operands, that is operands that are inputs for the operation
    • Result Operand Reference:  The operation may produce a result.
    • Next Instruction Reference:  This tells the CPU where to fetch the next instruction after the execution of this instruction is complete

Comments

Post a Comment

Popular posts from this blog

ONE DIMENSIONAL RANDOM VARIABLES: Handwritten notes

-
Properties of probability Distribution Function Expectation Value For the following problem by using Find the distribution function of x? What is the smallest value of x? for which probability P(X<=x)>0.5 for more click here ---------------------------------------------------------------------------------------------------------------- Continues Random Variable           We call the distribution function as probability density function f(x). Properties of probability density function.  click here ---------------------------------------------------------------------------------------------------------------- Moment Generating Function (MGF) Properties Additional property in MGF  for notes click here ---------------------------------------------------------------------------------------------------------------- Bernoulli Trial       For a single trail with only two possible res...
Read more

Design and Management of Computer Networks Running Notes

-
Architecture and Design Process Hierarchy and Inter-connectivity Network Supportability ------------------------------------------------------------------------------------------- Service Description pdf Service characteristics pdf Service Levels pdf System Components and network services pdf Service Requests and Requirements pdf Service Offerings pdf Service Matrices pdf Performance Characteristics pdf for running notes Download here ------------------------------------------------------------------------------------------- Types of user requirements pdf Timeliness Interactivity Reliability Presentation Quality Adaptability Security Affordability Functionality Supportability Future growth Requirement Analysis pdf The need for Requirement Analysis User Requirements pdf for running notes Download here -------------------------------------------------------------------------------------------  Ap...
Read more

Microprogrammed Control Unit for the Simple Computer

-
Image
In the case of a hard-wired control unit the control matrix is responsible for sending out the required sequence of signals.  Each bit of a microinstruction might correspond to one control signal.  If the bit is set it means that the control signal will be active; if cleared the signal will be inactive.  Sequences of microinstructions could be stored in an internal "control" memory.  Execution of a machine language instruction could then be caused by fetching the proper sequence of microinstructions from the control memory and sending them out to the data path section of the computer.  A sequence of microinstructions that implements an instruction on the external computer is known as a micro-routine.  The heart of the controller is the control 32 X 24 ROM memory in which upt to 32 24-bit long microinstructions can be stored.  Addresses provided to the control ROM come from a micro-counter register  The micro-counter, in turn, receiv...
Read more