Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Function of Control Unit-Assembly Language, Microprocessors and Computer Architecture-Lecture Slides, Slides of Computer Architecture and Organization

Assembly language is about computer basic operations. Its used in Computer Architecture. It also being used in Microprocessors. This lecture was delivered by Prof. Vishakha Ahuja at Guru Ghasidas University. It includes: Sequence, Arithmetic, Unique, ADD, MOVE, Segment, Accepts, Logic, Processin, Storage, Components, Fetches, Interprets

Typology: Slides

2011/2012

Uploaded on 08/03/2012

amritkala
amritkala 🇮🇳

4.4

(17)

92 documents

1 / 26

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
2
What is a program?
A sequence of steps
For each step, an arithmetic or logical operation
is done
For each operation, a different set of control
signals is needed
Function of Control Unit
For each operation a unique code is provided
e.g. ADD, MOVE
A hardware segment accepts the code and
issues the control signals
We have a computer!
docsity.com
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18
pf19
pf1a

Partial preview of the text

Download Function of Control Unit-Assembly Language, Microprocessors and Computer Architecture-Lecture Slides and more Slides Computer Architecture and Organization in PDF only on Docsity!

What is a program?

  • A sequence of steps
  • For each step, an arithmetic or logical operation is done
  • For each operation, a different set of control signals is needed

Function of Control Unit

  • For each operation a unique code is provided —e.g. ADD, MOVE
  • A hardware segment accepts the code and issues the control signals
  • We have a computer!

Components

  • The Control Unit and the Arithmetic and Logic Unit constitute the Central Processing Unit
  • Data and instructions need to get into the system and results out —Input/output
  • Temporary storage of code and results is needed —Main memory

Computer Components: Top Level View

Execute Cycle

  • Processor-memory —data transfer between CPU and main memory
  • Processor I/O —Data transfer between CPU and I/O module
  • Data processing —Some arithmetic or logical operation on data
  • Control —Alteration of sequence of operations —e.g. jump
  • Combination of above

Example of Program Execution

Instruction Cycle - State Diagram

Interrupts

  • Mechanism by which other modules (e.g. I/O) may interrupt normal sequence of processing
  • Program — e.g. overflow, division by zero
  • Timer — Generated by internal processor timer — Used in pre-emptive multi-tasking
  • I/O — from I/O controller
  • Hardware failure — e.g. memory parity error

Transfer of Control via Interrupts

Instruction Cycle with Interrupts

Program Timing Short I/O Wait

Program Timing Long I/O Wait

Multiple Interrupts - Sequential

Multiple Interrupts – Nested

Time Sequence of Multiple Interrupts

Connecting

  • All the units must be connected
  • Different type of connection for different type of unit —Memory —Input/Output —CPU

Input/Output Connection(1)

  • Similar to memory from computer’s viewpoint
  • Output —Receive data from computer —Send data to peripheral
  • Input —Receive data from peripheral —Send data to computer

Input/Output Connection(2)

  • Receive control signals from computer
  • Send control signals to peripherals —e.g. spin disk
  • Receive addresses from computer —e.g. port number to identify peripheral
  • Send interrupt signals (control)

CPU Connection

  • Reads instruction and data
  • Writes out data (after processing)
  • Sends control signals to other units
  • Receives (& acts on) interrupts

Buses

  • There are a number of possible interconnection systems
  • Single and multiple BUS structures are most common
  • e.g. Control/Address/Data bus (PC)
  • e.g. Unibus (DEC-PDP)

Address bus

  • Identify the source or destination of data
  • e.g. CPU needs to read an instruction (data) from a given location in memory
  • Bus width determines maximum memory capacity of system —e.g. 8080 has 16 bit address bus giving 64k address space

Control Bus

  • Control and timing information —Memory read/write signal —Interrupt request —Clock signals

Bus Interconnection Scheme

Big and Yellow?

  • What do buses look like? —Parallel lines on circuit boards —Ribbon cables —Strip connectors on mother boards - e.g. PCI —Sets of wires

High Performance Bus

Bus Types

  • Dedicated —Separate data & address lines
  • Multiplexed —Shared lines —Address valid or data valid control line —Advantage - fewer lines —Disadvantages - More complex control - Ultimate performance

Bus Arbitration

  • More than one module controlling the bus
  • e.g. CPU and DMA controller
  • Only one module may control bus at one time
  • Arbitration may be centralised or distributed

Centralised Arbitration

  • Single hardware device controlling bus access —Bus Controller —Arbiter
  • May be part of CPU or separate