I'm working with IT8172-based MIPS board and want to use one of (or may
be both) on-board timers.
For my purposes, it's required to generate irq from timer rarely, for
example, each 1 sec, or each 5 sec
or so. (The usage of Linux timer interface (init_timer() etc...) is
forbidden, and I don't want to touch
system timer to avoid the potential damage for basic timekeeping,
scheduling, etc.). I have two problems:
- timer backward counter is 16-bit wide and reaches zero too fast, even
starting from 0xffff;
- timer input clock may be one of CPU clock, CPU clock /4, CPU clock/8
or CPU clock /16, which looks
very fast too
So, the minimum interrupt frequency from both timers is 96 ints/HZ (with
TCR0.PST0 is 0 and
TCVR0 is 0xffff) and the maximum is around 150000 ints/HZ. Even the
minimum is too large for me...
It seems this question is much more about h/w than about Linux, but I
hope someone has an experience
with this arch :-) Is it possible to program on-board timer to generate
interrupts with less frequency ?