1kHz timer behavior on Cyclone V

[Janet Schneider]

Hello,


I am running a 1kHz timer test on the Altera Cyclone V dev board.  I am trying to measure the average time period between the timer firing, and any variance on that latency.


I'm seeing an average of 1003 microseconds between the timer firing.  About once a second, I see the maximum time between the timer firing go up to 2500-3000 microseconds.


I'm using rtems_clock_get_uptime_nanoseconds() to measure the time that the timer fires.  I have CONFIGURE_MICROSECONDS_PER_TICK set to 500.


Has anyone else seen this (or something similar)?  Any ideas what might be happening here?


Thanks,

Janet
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