How is time measured in computer systems?

Posted by DRK3 on Super User See other posts from Super User or by DRK3
Published on 2011-03-05T05:12:29Z Indexed on 2011/03/05 7:26 UTC
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cpu

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time

Something I have been puzzled about is this: how exactly does a computer regulate and tell time? For example: if I were to write a program that did this:

Do 2+2 then wait 5 seconds

How does the processor know what "5 seconds" is? How is time measured in computer systems? Is there a specific chip for that sole purpose? How does it work?

Thanks for any replies; I'm really interested in computer science, and would love any help you could give me =D.

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