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SubjectStrange behaviour of a cyclic task with HZ = 1024
Hi,

I have set the HZ constant to 1024 to increase the select resulution.
But the results of my measurements are not
as expected. I have a cyclical task (using select for timing) that
inverts a parallel port bit in each
cycle. I measure the high time with an oszillograph.

Here are my results:

15ms cycle: Everything as expected. The jitter is around 1ms
(corresponds to the 1000Hz).
10ms cycle: The cycle is either 10ms or 20ms. No values between.
5ms cycle: The cycle is either 10ms or 15ms. No values between.

Do you have any explanations for this behaviour? Is there a better way
to increase to resolution of the select call?

Peter

P.S: I found that the HZ constant is used in the tcp code. Do I have to
expect any errors coming from the changed HZ value?



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