powerpc mvme5500 clock off by factor of 150

Feng, Shuchen feng at bnl.gov
Mon Mar 7 17:44:35 UTC 2005

"Joel Sherrill " wrote:

> Kate Feng wrote:
> > Peter Dufault wrote:
> >
> >
> >>The clock on the MVME5500 seems to be off by a factor of 150.  In the
> >>"ticker" test it is taking 750 seconds instead of 5 seconds for the
> >>displays of the times.  I started fiddling constants in bspstart.c but
> >>then reading the I2C bus started to fail so I decided I had to look
> >>through things and get an overview and not continue ignorantly.
> >>
> >>I'm looking through it now, but if anyone has hints based on knowledge
> >>of the PPC decrementer and the PPC board support packages and how they
> >>support the clock (or maybe changes that went into 4.7?) on where I
> >>should look I'd appreciate it.
> >>
> >
> >
> > I  never tested the tests/samples/ticker.  However, the mvme5500 clock
> > works fine for me.  Attached is a test program I  wrote.  The test
> > is:
> This is using rtems_bsp_delay.  This is not the same as the
> ticker test which uses that the clock tick device driver.
> Look in tests/samples/ticker.  You need to run it or
> you can't be sure any RTEMS time related service including
> timeouts on blocking, sleep, etc are right.

I do not have to test  tests/samples/ticker.  My EPICS applications
use timeouts on blocking, sleep, etc.  The clock works fine on all my

Anyway, I have a look at the code :
    status = rtems_task_wake_after( task_index * 5 * get_ticks_per_second()

Thus the time it takes is subject to the value of task_index.
That is how he can get the factor of 5 seconds, right ?
Peter, can you print out what the value of task_index is ?


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