Interrupt Handling Methods

• Multiple Interrupt Lines: The simplest technique is to use a large number of interrupt lines (Multiple Interrupt Lines) between the CPU module and I / O.
• Software Poll: The process, if the CPU is aware of an interrupt, the CPU will go to service interruption, perform functions poll the entire I / O module to determine the module interrupt, The disadvantage is the need of time because they have to identify all the modules to determine the I / O module that implements interrupt.

 

• Daisy Chain: A daisy chain more efficient, which uses hardware poll. The entire I / O module is connected to CPU interrupt channel chain. If there is an interrupt request, the CPU will run acknowledge signals running on the interrupt line to find the I / O module that sends an interrupt. 
• Bus arbitration: In this method, first, the module I / O gain control of the bus before the module uses an interrupt request channel. Thus there is only an I / O module can interrupt. 

System Design Bus

1. Type of Bus

• Dedicated: Data Bus and Address Bus has a separate line, the design is more expensive and the data transfer rate is higher.
• Multiplexed: Line Data and Address rolled into one, plan cheaper and the data transfer rate is slower.

 

  

 

     

 2. Method arbitration

• Centralized.
• Distributed.

 3. Timing

• Synchronous.
• Asynchronous.

 4. Bus width

• Address
• Data 

 5. Type of data transfer

• write.
• Read.
• Read modify write.
• Read after write.
• Block.

 

Physical Characteristics of Memory

1. Volatile ~ Non-Volatile 

• Volatile memory: A temporary memory that loses its contents when the computer or hardware device loses power, memory storage type is not permanent.  

SDRAM

    Example: RAM (EDO-RAM, SDRAM, DDRAM).

• Non-Volatile memory: A memory that keeps its contents even if the power is lost, storage in this type of memory is permanent.

Computer Generation 1 ~ 5

-  Computer Generation -1(1941-1956):

IBM 650Magnetic Drum Calculator

• Use of Vacuum tubes and magnetic drums (for data storage).
• Larger AC were needed.
• Programming in Mechanical Language.
• High Electricity Consumption .
• Big & Clumsy.

- Computer Generation -2(1956-1963):

Computer G-2

• The main components: Transistor.
• Higher processing speed.
• Core Memory was developed.
• Smaller size.
• Using a high level programming language..
• First Operating System was developed.

RAID(Redundant Array of Independent Disks)

Definition RAID: a method of storing data on multiple hard disks and collection of disk drives that are considered by the operating system as a single logical drive, Redudant disk capacity is used to store parity information to ensure recoverability of data disk failure.

    Types of RAID: 

RAID

1. RAID-0: This technique has striping but no redundancy of data. Data on the track and spread to the entire disk, RAID-0 has a High-Speed ​​Access, Data search performed parallel and Multiple data requests do not happen in a single disk.

Cache Mapping

Definition Cache Mapping: To determine the link between the data in the Main Memory address with the address data, when in Cache Memory.

Mapping

3 Mapping Techniques: 

1. Direct Mapping: a method of storing information for easy access on a computer.  

          

          Properties:  

• Searching process the data in the cache faster.
• Each piece of data in memory is assigned a space in the cache, which it shares with other pieces of data. 
• The data in the cache has a sequential slot number.
• If often happens "swapping" in the cache it will degrade the performance of Cache.
• Cache data is constantly being overwritten as new data is needed

Operating System

Definition Operating System: Set of programs that manage computer hardware resources, serves to control the execution of application programs and the "interface" between the user machine hardware.

Task Operating System:

1. Controlling the computer resources.
2. Provides services for programming.
3. Scheduling program execution.

Operating System

Advantages Use of Operating System:

1. General and can apply to all.
2. Can allow you to use computer without having the coding knowledge.   
3. The computer can be operated with a more comfortable and easier.
4. Computer resources can be used more efficiently. 
5. Supports the hardware of the computer and it enables the execution of short programs of the computer. 

Concepts and Module I / O

Definition I/O: A part of computer structure, function as a gateway for the CPU to interact with their environment.

Definition Modul I/O: A hardware interface for the system bus or central switch and control one or more peripheral devices and these devices contain logic to perform the functions of communication between peripherals and computer bus.

Definition Peripheral: A device that's connected to a host computer that interacts with the CPU via the Module I/O.

Cache Memory

   Cache memory is random access memory that a computer microprocessor can access more quickly than it can access regular RAM.

Property:

• Fast memory with a little capacity.
• It could be placed in a separate CPU chip or module.
• Located between the main memory to the CPU.
• If it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory. 

How Cache memory works? 

1. CPU requests contents of the data, from specific memory locations.
2. Then, checking the data in the cache.
3. If the data is exist, directly taken from the cache (fast).
4. If there is no data, read one block of data from main memory to cache.
5. then, the data is retrieved from the cache to the CPU.

External Memory

   Definition: External memory is a type of data storage device for a computer that is kept outside of the computer in its own casing and the memory used by the CPU for data and program storage purposes in the amount of volume. Example: Hard Disk, Magnetic Tape, CD-ROM.

External Hard Disk

Properties:

• External memory is also called Secondary-Memory has a relatively large size of the volume, as great as Tera Byte (TB), is used as a "storage" or storage of data and programs.
• Programs and data are stored normally in a dormant state, for example in the form of compressed, or programs that have not been installed.
• Having the data access speed is relatively slow when compared with Random Access Memory. 

Memory Access Method

 There are 4 Memory Access Method:

 
1. Sequential Access Method

Sequential Access

• Data access is very slow, because the data will be sorted access serially one by one.
• Data access is done sequentially, such as on magnetic tape.

    Example: Magnetic Tape, Cartridge Back Up.

 

2. Direct Access Method

Direct Access

 

• obtain data from a storage device by going directly to where it is physically located on the device rather than by having to sequentially look for the data at one physical location after another.
• Data-access relatively quickly, compared Sequential Access.

    Example: Hard Disk, Floppy Disk (floppy).

BUS System

   Definition: BUS is a means of transporter / channel contained within a microprocessor (CPU) that connects the microprocessor to the outside world, Only devices addressed by the signals pay attention to them, the others discard the signals.

The microprocessor (CPU), there are 3 basic BUS system:

•  Data BUS        (bi-directional)
•  Address BUS     (uni-directional)
•  Control BUS     (uni-directional)  

A .Data Bus  

• Handles the transfer of all data and instructions between  functional areas of the computer. 
• The data bus is usually used as a taxonomy of microprocessor concerned.
• Only transmit in one direction at a time.
• Used to transfer instructions from memory to the CPU for execution.
• Used to transfer data between memory and the I/O section during input/output operation.

BUS

Basic structure Cpu & Control Unit

CPU: Basic Structure

CPU diagram

There are 3 parts:

• Control Unit, used to control the operation of the CPU and control the computer as a totality.
• Arithmetic Logic Unit (ALU), serves to establish a computer data processing functions.
• Register, serves as an internal storage for the CPU.

Basic Structure of Computers

There are four main structures:

Computer Basic Structure diagram

• Central Processing Unit (CPU), serves as the central control computer operations and processing functions - functions of the computer.
• Main Memory, serves as data storage. 
• I/O, function to move data between the main memory to the external environment or other devices.
• System Interconnection, serves as a system that connects the CPU, main memory and I / O.

Definition of Computer Architecture & Computer Organization

   Computer Architecture is Defined As The Functional Operation Of The Individual H/W(HardWare) Unit In A Computer System And The Flow Of Information Among The Control Of Those Units, in other words definition of computer architecture is a part of the computer system attributes associated with a programmer, Example: instruction sets, arithmetic is used, addressing techniques, mechanisms of I / O.

Desk Computer

   Computer Organization is a part of the operational units and interconnection between components of the computer system in the realization of its architectural aspects, Example: device interface, memory technology, system memory, and control signals.