external to internal oscillator switching at running

[deepakomanna]

Dear Sir,
here i am using 16f913, MPLAB 7.5 Ver. & CCS PCM C Compiler, Version 3.249, 34534.
Here i want to use external oscillator as well as internal oscillator
i.e.If my input frequency is <297 i have to use external crystal(32.768 khz)
if greater i have switch to internal oscillator.Also in fuses i declared
#fuses intrc_io &
#use delay(clock=8000000)
so if i switched to external what changes i have to make.
Actually what i am doing is,
if my freq<297, i have to increse the count every 1 sec i.e.1 minute == 1 minute
and display on the static LCD. for this i am using timer 0 interrupt.
And if it is 298 to 594 hz. use internal clock & display 1 minute == 2 minute
In this i am using CCP1 interrupt to measure time between two pulses.
any help would be appriciated...
_________________
Thank You,
With Best Regards,
Deepak.