[ECOS] Changing system timer resolution

Grant Edwards grante@visi.com
Sun Nov 18 23:57:00 GMT 2001


On Wed, Nov 28, 2001 at 10:31:07AM -0700, Gary Thomas wrote:

> > > It would be awfully nice if there were a simple way for an
> > > application to determine the system timer tick resolution (e.g.
> > > macros/functions to convert back and forth between
> > > seconds<->ticks and ms<->ticks).  I know this information is
> > > available, but it's buried pretty deeply and is difficult to
> > > use.
> > 
> > I absolutely agree with the statement above. Currently, I am using some
> > "home-made" calculations and macros in my applications (i.e. for
> > cyg_thread_delay()) and they look quite awkward. Some 'easy to use'
> > conversion between real time and system tick in any form (API, macro) would
> > be quite useful.
> 
> > Digression:
> > Also, it would be nice to have some high-resolution performance counter for
> > more precise time handling. For example, microsecond handling is quite
> > common in today's RTOS applications. The high-resolution counter shouldn't
> > be limited by system timer tick resolution, but with the underlying hardware
> > clock resolution.
> 
> This is already available using the HAL_CLOCK_READ() functionality.  
> Look for examples of how to use it in the 'tm_basic.cxx' test program.

I think that only solves one side of the problem.  The other
side is when you want an event to happn 7354us from now.

-- 
Grant Edwards
grante@visi.com



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