A Top-Level View Of Computer Function And Interconnection Chapter 3 Lecture 07 Faheem ahmad Lecturer, CNET Dept., Jazan University, Jazan KSA A Top-Level View Of Computer Function And Interconnection

Interrupt Interrupt: It is a condition that cause microprocessor to temporarily work on the other task, and then again return to previous. Book Page No 74

Transfer of control via interrupts. the processor and the oper­ating system are responsible for suspending the user program and then resuming it at the same point. When the interrupt processing is completed, execution resumes . Interrupt handler: determines the nature of the interrupt and performs whatever actions are needed Book Page No 76

Multiple interrupts During execution of program if more then one interrupt is there then it is called as multiple interrupts. A typical system can support several to several dozen interrupts, if there are multiple interrupts then how these interrupts are handled by the system. For this situation, system gives priority to the various interrupt. At the start of interrupt cycle, the high priority interrupt will be serviced first then rest services in turn. Book Page No 78

Multiple interrupts Book Page No 81

Classes of interrupt 1.Program: is caused by condition as result of instruction execution, e.g. divide by zero 2.Timer: Generated by timer within processor. 3.I/O: Generated by I/O to signal completion or error condition. 4.Hardware failure: Generated by failure such as power failure or memory parity error.

Interrupt cycle Interrupt cycle: It means interrupt is added to instruction cycle. Processor checks for interrupt. If there is no interrupt CPU continues with fetch and execute process. If there is Interrupt suspend execution of current program Save its context Set program counter to start of interrupt

Instruction cycle with interrupts Book Page No 77

Thank you!!!