hi,

"CH/CL becomes more than CCAP30L/H, but irq subroutine doesn't starts"

A compare interrupt was always generated on equal not on less or above.

Here we talk about two different things:
- interrupt request which is generated when the match occurs;
- ISR execution which is possible at the corresponded conditions.

Original poster should post his code or provide more details. At least, I cannot understand the problem yet.

Regards,
Oleg