we know that there are many pins available in microprocessor chips one of them is INTR(interrupt Req)
When a CPU receives an Interrupt Request (IRQ), it first checks if it must react to the interrupt. So-called Maskable Interrupts allow a programmer to specify that the CPU does ignore it, while Non-Maskeable Interrupt requests must be serviced. now if a process wants a control of CPU it sends a positive signal on INTR pin this will interrupt CPU n this is how CPU is being interrupted. after that CPU stops its current processing ........ I think now its clear Regards Pradeep On Sun, May 2, 2010 at 10:25 PM, praba garan <prabagara...@gmail.com> wrote: > @ Pradeep > > *CPU stop its current processing and goes to the interrupt subroutine* > > you have mentioned that the CPU stops its current processing and goes to > the interrupt subroutine.. > > My Question is how does the CPU stops its execution(any special hardware > involved) because it is busy in executing the current instruction. > > > With Regards, > Prabagaran. > > > > On Sun, May 2, 2010 at 4:02 AM, pradeep verma <ppradeep...@gmail.com>wrote: > >> lets suppose Processor executing a instruction(process1) and another >> process2 tries to take the control of CPU so inorder to inform CPU it has to >> interrupt the CPU right >> now we know that if interrupt comes CPU stop its current processing and >> goes to the interrupt subroutine...now CPU knows that its a pre-emption >> interrupt so CPU first run its short term scheduler(this will inform CPU >> that the interruting process priority is less or greater ..n if greater than >> CPU goes to previous process1 preempt it and start executing higher priority >> process2 ) >> >> I think its clear >> >> Regards >> Pradeep >> >> >> >> On Sun, May 2, 2010 at 3:06 AM, praba garan <prabagara...@gmail.com>wrote: >> >>> @ Guillermo Garcia >>> >>> The link gives the overall abstract idea. >>> I am talking in register level. >>> When a user process executes >>> >>> 1. PC program counter will contain the address of the next instruction in >>> user code. >>> 2. Processor registers(accumulator ...) contain the current instruction >>> data. >>> >>> Then where does the interrupt actually arrives?? >>> >>> And by that time the user process the control, then who does the >>> preempting and how?? >>> >>> With Regards, >>> Prabagaran. >>> >>> >>> >>> On Sun, May 2, 2010 at 2:35 AM, Guillermo Garcia >>> <gegarci...@gmail.com>wrote: >>> >>>> >>>> read here -> http://en.wikipedia.org/wiki/Preemption_%28computing%29 >>>> >>>> >>>> >>>> Time slice >>>> >>>> The period of time for which a process is allowed to run in a preemptive >>>> multitasking system is generally called the *time slice*, or *quantum*. >>>> The scheduler is run once every time slice to choose the next process to >>>> run. If the time slice is too short then the scheduler will consume too >>>> much >>>> processing time. >>>> >>>> An interrupt <http://en.wikipedia.org/wiki/Interrupt> is scheduled to >>>> allow the operating system<http://en.wikipedia.org/wiki/Operating_system> >>>> kernel <http://en.wikipedia.org/wiki/Kernel_%28computer_science%29> to >>>> switch between processes when their time slices expire, effectively >>>> allowing >>>> the processor’s time to be shared between a number of tasks, giving the >>>> illusion that it is dealing with these tasks simultaneously, or >>>> concurrently. The operating system which controls such a design is called a >>>> multi-tasking system. >>>> >>>> >>>> >>>> >>>> On Sat, May 1, 2010 at 5:26 PM, praba garan <prabagara...@gmail.com>wrote: >>>> >>>>> @ Guillermo Garcia >>>>> >>>>> Suppose a user program is executing and and clock interrupt arrives.. >>>>> Then who receives the interrupt?? >>>>> Can you xplain me the clock interrupt(like any hardwares involved) bit >>>>> detailed?? >>>>> >>>>> With Regards, >>>>> Prabagaran. >>>>> >>>>> >>>>> >>>>> On Sun, May 2, 2010 at 1:38 AM, Guillermo Garcia <gegarci...@gmail.com >>>>> > wrote: >>>>> >>>>>> The scheduler takes control with a clock interruption. Then it >>>>>> analyzes if it has to preempt or not the running task. >>>>>> >>>>>> On Sat, May 1, 2010 at 5:00 PM, praba garan >>>>>> <prabagara...@gmail.com>wrote: >>>>>> >>>>>>> Hi all, >>>>>>> I have a doubt in OS. >>>>>>> The scheduler does the process of preemption. >>>>>>> And one processor can run atmost 1 instruction at a time. >>>>>>> Then how & where does the scheduler run?? >>>>>>> >>>>>>> With Regards, >>>>>>> Prabagaran. >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "Algorithm Geeks" group. >>>>>>> To post to this group, send email to algoge...@googlegroups.com. >>>>>>> To unsubscribe from this group, send email to >>>>>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>>>>> . >>>>>>> For more options, visit this group at >>>>>>> http://groups.google.com/group/algogeeks?hl=en. >>>>>>> >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "Algorithm Geeks" group. >>>>>> To post to this group, send email to algoge...@googlegroups.com. >>>>>> To unsubscribe from this group, send email to >>>>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>>>> . >>>>>> For more options, visit this group at >>>>>> http://groups.google.com/group/algogeeks?hl=en. >>>>>> >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Algorithm Geeks" group. >>>>> To post to this group, send email to algoge...@googlegroups.com. >>>>> To unsubscribe from this group, send email to >>>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>>> . >>>>> For more options, visit this group at >>>>> http://groups.google.com/group/algogeeks?hl=en. >>>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Algorithm Geeks" group. >>>> To post to this group, send email to algoge...@googlegroups.com. >>>> To unsubscribe from this group, send email to >>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/algogeeks?hl=en. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Algorithm Geeks" group. >>> To post to this group, send email to algoge...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/algogeeks?hl=en. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To post to this group, send email to algoge...@googlegroups.com. >> To unsubscribe from this group, send email to >> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >> . >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algoge...@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. 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