Control unit
1 / 20

Control Unit - PowerPoint PPT Presentation

  • Uploaded on

Control Unit. TEAM 1: Miguel Harmant Rodney Rodriguez Elias Crespo Javier Parra Alfredo Alonso Marc-Wayne Anglin. Basic concepts. WHAT IS A MICRO-INSTRUCTION?. Single instruction in a micro-program. . WHAT ARE MICRO-OPERATIONS?.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Control Unit' - kin

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Control unit

Control Unit


Miguel Harmant

Rodney Rodriguez

Elias Crespo

Javier Parra

Alfredo Alonso

Marc-Wayne Anglin

Basic concepts
Basic concepts


  • Single instruction in a micro-program.


  • Smaller series of steps that compose a micro-instruction.

  • Atomic operation by the CPU.


  • Data transfers between registers.

  • Data Transfer from registers to memory

  • Data transfer from memory to registers

  • Logic and arithmetic operations.

Basic components of the cpu
Basic components of the cpu

  • ALU - does the actual computation or processing of data.

  • Registers - set of internal memory.

  • Internal Data paths (Bus) - need to transfer data between the various registers and the ALU.

  • External Data paths - distribute data to other components.

  • CONTROL UNIT -controls the movement of data and instruction into and out of the CPU and controls the operation of the ALU.

Cpu structure
Cpu structure

What is the control unit
What is the control unit ?

  •  Is the circuitry that controls the flow of information through the CPU.

  •  It coordinates the micro-operations of other units within it.

  •  In other words, it is the brain within the brain.

Basic functions of the cu
Basic Functions of the cu

  • Sequencing

    • Stepping through the micro-instructions.

    • Maintaining proper sequence.

  • Execution

    • Interpreting input signals into output control signals.

    • Executes Control signals.

Example of the cu operations
Example of the cu operations

  • MAR <- (PC)

    • Control unit activates signal to open gates between PC and MAR 

  • MBR <- (memory)

    • Open gates between MAR and address bus

    • Memory read control signal

    • Open gates between data bus and MBR

  •  IR <- (MBR)

    •  Open gates from MBR to Instruction Register


    Control signal Sequence

    Types of control unit
    TYPES OF control unit

    • Hard-wired

      • Designed as a combinatorial and sequential logic circuit.

      • Input logic signals are transformed into output logic signals, which are the control signals.

      • Faster.

    • Micro-programmed

      • The control signal values for each micro-operation are stored in memory.

      • Micro-operations that compose control signals are read from memory.

      • Simpler to modify and construct.

    RISC architecture

    CISC architecture

    Components description
    Components description

    • Instruction Decoder

      •  Takes the input from the op-code field of the instruction register and activates one of its 8 output lines.

      •  Each line corresponds to one of the instructions in the computer's instruction set.

      • Different Control Signals are produced depending on the op-code.

    Components description continued
    Components description (continued)

    • Ring Counter

      • Continuously cycles from t0 to t5.

    • Control matrix

      • It receives input from the ring counter and the instruction decoder and provides the proper sequence of control signals.

    Review questions
    Review Questions?

    • What are the basic micro-operations?

    • What are the three main components of the CPU?

    • What is the Control Unit?

    • What are the two basic functions of the Control Unit?

    • What are the two types of Control Unit?

    • How are they constructed?

    • What is RISC and CISC?

    • Which are the differences between the two types of Control Unit?

    • What are the advantages of each?

    • What are the disadvantages of each?