Systems Programming Lecture Compute.pptx

CSC 334-Systems Programming -2020-2021 Session- Lecture 1-Computer Organization.pptx

1. Computer Organization CSC 334-Systems Programming 2020/ 2021 Session Lecture-1

2. Unit-1: Computer Organization Computer organization: It refers to the operational units and their instruction that realize architectural specification. Computer organizational attributes include hardware details transparent to the programmer, such as control signals, interface between the computer memory and input/output mechanism. Example: Building Capacity of 3000 people How building will reach the ability of 3000 people

3. Computer Organization … By Organization view, the computer is divided into three components: the processor: the main part of the computer. Its task is to execute the program using the control unit (CU ) the memory: simply stores the information written in it the I/O processor: interface the computer to access the outside world The Control Unit: 2 parts the Arithmetic and Logical unit (ALU), and the registers

4. Computer Organizations… Registers Register  are used to quickly accept, store, and transfer data and instructions that are being used immediately by the Central Processing Unit (CPU). Types of Registers Accumulator (AC) Data Register (DR) Address Register ( AR) program counter  (PC) Memory Data Register  (MDR) Index register (IR) Memory Buffer Register (MBR)

5. Registers Types … Memory Address Register (MAR) Holds memory address of data and instructions Used to access data and instructions from the memory CPU places the address of required memory locations in MAR Program Counter Also known as Instruction Pointer Sometimes called Instruction Address Registers (IAR) It is a 16-bit special function processor Register It keeps tracks of the next memory address of the instruction to be executed Accumulator Used for storing the results that are produced by the system

6. Register Types … Memory Data Register (MDR) It is the register of the Control Unit Contains the data to be stored or fetched in the computer storage e.g. RAM It acts like a buffer and holds anything that is copied from the memory ready for the use of the processor It is a two way registers It stores data fetched from the memory Data to be written from other CPU registers could be placed on MDR The Memory Data Register is half minimal Interface between a micro program and computer storage

7. Register Types … Index Register (IR) Hardware element which holds a number that can be added or removed from the address portion of a computer instruction to form an effective address Also known as Base Register It is a processor register for modifying operand addresses during the run of a program Memory Buffer Register (MBR) Holds the contents of data or instruction read from or written to memory Data Register Used to temporarily store data being transmitted to and fro a peripheral device A fast storage units where a few pieces of information can be stored temporarily until needed

8. Computer Organization… Registers are used by the  CPU for performing some required operations . A user gives some inputs to the system the input is stored in the Registers  and the system gives us the results after processing the inputs. The result is also stored in the Registers so that they are used by the  CPU for processing the data which is given by the user Registers in the Memory Hierarchy Memory Hierarchy is an enhancement to organize the memory such that it can minimize the access time The Memory Hierarchy was developed based on a program behavior known as Locality of References .

9. Computer Organization… Memory Hierarchy

10. Computer Organization…

11. Computer Organization… Operations Performed by Registers      Fetch : Registers use the Fetch Operation to take the instructions given by the user and those stored into the Main Memory .      Decode : The Decode Operation is used for interpreting the instructions . In order words, it means the instructions are decoded by the CPU which then determines the operation to be performed on the instructions .      Execute : The Execute Operation is performed by the CPU. The Results that are produced by the CPU are then stored into the memory after which they are displayed on the user Screen.

12. Computer Organization… Register Organization They serve two functions: 1. User-Visible Registers - enable the machine- or assembly- language programmer to minimize main-memory references by optimizing use of registers 2. Control and Status Registers - used by the control unit to control the operation of the CPU and by privileged, OS programs to control the execution of programs

13. Ports, Codes, Data and Stack Segments Ports A Computer Port is an interface or a point of connection between the computer and its peripheral devices. Some of the common peripherals are mouse, keyboard, monitor or display unit, printer, speaker , flash drive The main function of a computer port is to act as a point of attachment A computer port is also called as a Communication Port the female end of the connector is referred to as a port and it usually sits on the motherboard communication ports can be divided into two types Serial Ports and Parallel Ports

14. Ports… A serial port This is an interface through which peripherals can be connected using a serial protocol which involves the transmission of data one bit at a time over a single communication line A parallel port on the other hand, is an interface through which the communication between a computer and its peripheral device is in a parallel manner i.e. data is transferred in or out in parallel using more than one communication line or wire. Printer port is an example of parallel port

15. Ports… Types of Ports and Applications… PS/2 PS/2 connector is developed by IBM for connecting mouse and keyboard It was introduced with IBM’s Personal Systems/2 series of computers and hence the name PS/2 connector PS/2 connectors are color coded as purple for keyboard and green for mouse PS/2 is a 6-pin mini DIN ( Deutsche Institut fuer Normung ) connector   DIN is a German standardization group It is still sometimes found on all IBM compatible computers.

16. Types of Ports and Applications … PS/2 Computer keyboards, computer mice, network routers, video appliances, and Apple serial devices are a few examples of hardware devices that may use a DIN style of  connector The right illustration is of the actual PS/2 male connection with its pin layouts.

17. Types of Ports and Applications … PS/2