ERC32 ticks

Joel Sherrill joel.sherrill at oarcorp.com
Mon Oct 16 15:12:12 UTC 2006


Aleix Conchillo Flaqué wrote:
> Hi,
>
> I'm trying to run some simple examples based on timers and there are  
> some things I don't quite understand.
>
> I've seen that the ERC32 BSP uses the RTC as the clock driver, which  
> is in charge of calling rtems_clock_tick() (from the ISR) which  
> increments the internal tick counters (TOD, Watchdog, ...).  
> Everything fine, by now.
>
> Then, I've used the rtems_clock_get with  
> RTEMS_CLOCK_GET_TICKS_SINCE_BOOT to get the current ticks since boot,  
> and it has returned me 100 (I haven't configured anything). Is this  
> correct? With this value I can't even have millisecond precision,  
> thus calling RTEMS_MILLISECONDS_TO_TICKS (1234) I get 123 ticks,  
> which is correct for the 100 ticks given, but doesn't make much sense.
>
> This might be obvious, am I missing something?
>
>   
Only that you need to set CONFIGURE_MICROSECONDS_PER_TICK to match what
your application requires balancing overhead with timing granularity 
required.

#ifndef CONFIGURE_MICROSECONDS_PER_TICK
#define CONFIGURE_MICROSECONDS_PER_TICK 
RTEMS_MILLISECONDS_TO_MICROSECONDS(10)
#endif



> Thanks in advance.
>
> Regards,
>
> aleix
> _______________________________________________
> rtems-users mailing list
> rtems-users at rtems.com
> http://rtems.rtems.org/mailman/listinfo/rtems-users
>   




More information about the users mailing list