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How convert the jitters to a TICK

Posted by Bill Yang on April 14, 2009

I have a question how to add the jitters to a timer expires. For instance,
//declare a time,
struct timer periodic_timer;
// start a timer in period of two seconds
timer_set( &periodic_timer, configTICK_RATE_HZ * 2 );
// since there are jitters, when timer expired and reset, I need to add these jiffters. below is code.
if( timer_expired( &periodic_timer ) ){
periodic_timer.interval += (( ulMaxJitter * mainNS_PER_CLOCK ) / mainNS_PER_TICK);
timer_reset( &periodic_timer );

..... do something.....
// Note: ulMaxJitter is measured by the high freq task.
mainNS_PER_CLOCK is 20ns.
Because configTICK_RATE_HZ is 200, so mainNS_PER_TICK is 5000000ns.
I wonder if above code is correct?
Bill Yang

RE: How convert the jitters to a TICK

Posted by Richard on April 15, 2009
Please do not create multiple threads on the same topic.


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