With the aid of a diagram, describe what happens during the “fetch-execute” cycle. Include a description of how interrupts are detected.

With the aid of a diagram, describe what happens during the “fetch-execute” cycle. Include a description of how interrupts are  detected. List various types of interrupts. Also explain in detail what  happens when an interrupt occurs

Fetch/Execute Cycle

The fetch-execute cycle of the processor refers to the sequence that is completed for each instruction in a program.

• Fetch Sequence

1. Move the value in the program counter to the memory address register
2. Send the value in the memory address register to memory via the address bus
3. Return the value stored in memory via the data bus
4. Store the value in the memory data register
5. Copy the instruction from the memory address register to the instruction register
6. Increment the program counter. The instruction in the instruction register is then Decoded

• Execute Sequence

1. The instruction is Executed

Types of Interrupts

Generally there are three types o Interrupts those are Occurred For Example

1)   Internal Interrupt

2)   Software Interrupt.

3)   External Interrupt.

The External Interrupt occurs when any Input and Output Device request for any Operation and the CPU will Execute that instructions first For Example When a Program is executed and when we move the Mouse on the Screen then the CPU will handle this External interrupt first and after that he will resume with his Operation. 

The Internal Interrupts are those which are occurred due to Some Problem in the Execution For Example When a user performing any Operation which contains any Error and which contains any type of Error. So that Internal Interrupts are those which are occurred by the Some Operations or by Some Instructions and the Operations those are not Possible but a user is trying for that Operation. And The Software Interrupts are those which are made some call to the System for Example while we are Processing Some Instructions and when we wants to Execute one more Application Programs.