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Altera_Forum's avatar
Altera_Forum
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13 years ago

Nios II timer and erroneous usleep() results

I am using a Nios II processor running at 50MHz with a timestamp timer and a system timer. I am noticing that the usleep() function is not returning expected time delays. For the code: frame_...
Altera_Forum's avatar
Altera_Forum
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13 years ago

usleep() resolution is almost certainly limited by some time interrupt - it will only return after the relevent interrupt.

In order to guarantee the minumim sleep time it is also likely that one clock period is always added.

If you preceed the code above with another usleep() call, and then vary the interval you'll see the quantisation (etc).