1. A Top-Level View Of Computer Function And Interconnection
Chapter 3
Lecture 06
Faheem ahmad
Lecturer, CNET Dept.,
Jazan University, Jazan KSA
A Top-Level View Of Computer Function And Interconnection

2. Topics of this chapter Computer components Computer functions
Instruction fetch and execute
Interrupts
Interconnection structure and
Bus Interconnections

3. Von Nuemann Three key concepts
1. Data and Instruction are stored in memory. 2. The contents of memory are addressable by location. 3.Execution occur sequentially.

4. Components There are 3 components of a computer.
Central processing unit
Memory unit
Input and Output unit
CPU is the place where actual processing is done on data.
The main component of CPU is control unit, the function of control unit is to control computer’s memory, ALU performs computer data processing.
Memory Unit stores the data given by the input device.
Input and Output Unit is responsible for sending data in and getting processed data out.

5. Hardwired program
Process of connecting various components in configuration to form a program.

6. software
A sequence of codes or instruction is called software.

7. Instruction Cycle Two steps: Fetch Execute Book Page No 70
Instruction Cycle Processing required for a single instruction is called an instruction cycle.
Basic instruction cycle consists of the following phases: a. b. c. d. Fetch and instruction from memory. Decode the instruction. Read the effective address from the memory, if the instruction has an indirect address. Execute the instruction.
Book Page No 70

8. Fetch: The processor reads (fetches) instructions from memory one at a time and executes each instruction.
Execute: Program execution consists of repeating the process of instruction fetch and instruction execution.

9. Fetch Cycle
Processor fetches instruction from memory location pointed to by PC
Program Counter (PC) holds address of next instruction to fetch
Increment PC
Book Page No

10. Execute cycle Instruction loaded into Instruction Register (IR)
Processor interprets instruction and performs required actions:

11. Continue.. Actions Processor-memory Processor I/O Data processing
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
Book Page No

12. Thank you!!!