interupt timer frequency ?

[gck]

timer frequency

It is commen to have interupt timer works on less frequency than the processor operating frequency. Whay it is so?
any special reason.
Please let me know any article addressing this issue.

 

[btbass]

i have timer frequency

One reason is that most systems need a clock for timing. If you set the interrupt to interrupt every 1mS and then increment a counter in the interrupt, you have a global clock to use by your program for timing.
It would be impractical to set the interrupt to the same frequency as the system clock, the program would spend all its time servicing the interrupt.