Why are oscillators used?

[stuboy78]

Hi

I have seen oscillators being used with uC chips... whats their use there?

ive read that they set a frequency... but what frequency?

lets say an osc of 4 MHZ is used... that means it oscilates 4000 times a sec right?

now when it oscilates 4000 times a second, how does it help the uC chip? isnt the internal programming we do not enough to do the repetitions? or any circuit for that matter.... pls explain in simple language.

 

[Nigel Goodwin]

MHz is million times, so 4MHz is 4,000,000 per second.

It's the clock for the processor, everything is controlled by that clock - without a clock, nothing can happen (although some devices have optional internal clocks, but it's still there).

 

[arunb]

even your heart has a clock (a biological one) thats the way it pumps blood rhythmically day in and day out...

 

[crutschow]

A µC does it's program tasks by performing a series of many steps. The rate of sequence of the steps is controlled by the clock, one step per clock cycle. Thus the faster the clock the µC can have, the faster it can perform the steps and thus the program.

They actually have a type of processor that doesn't require a clock which uses asynchronous logic, but so far it's mainly in the research stage.

 

[Hero999]

4000 times per second is 4kHz, as Nigel said 4MHz is 4000,000 times per second.

SI prefix - Wikipedia, the free encyclopedia

Modern CPUs run at GHz frequencies, 1000,000,000 times per second.