[En-Nut-Discussion] 32.768kHz crystal

Alastair Jeremy ajeremy at dotaussie.com.au
Tue Dec 31 00:20:37 CET 2002

Hi Harald,

I am just wondering - do you actually use the 32.768kHz crystal for anything
in the O/S? Or is it just there for something one of your applications uses?

I could only find some references to it in timer.c, where it appears that
you use it to try to figure out what the CPU frequency is. But there are a
lot of things commented out, and it looks like the whole use of the
32.768kHz crystal disappears if you define NUT_CPU_FREQ. (Which appears to
be in the MakeDefs file, but is commented out). I gather that you then use
Timer0 linked to the CPU clock for the real timer events?

So, is the use of the 32.768kHz crystal unnecessary if I recompile Nut/OS
with NUT_CPU_FREQ defined?



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