diff options
| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2006-03-07 21:05:28 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2006-03-07 21:05:28 +0000 |
| commit | 75bf564ba18652d4392c77e2efebfd47478d34a9 (patch) | |
| tree | dbab82075f9a1367bc6f9ef5f5f511df629d7412 /c | |
| parent | 2006-03-07 Till Strauman <strauman@slac.stanford.edu> (diff) | |
| download | rtems-75bf564ba18652d4392c77e2efebfd47478d34a9.tar.bz2 | |
2006-03-07 Lars Munch <lars@segv.dk>
* at91rm9200/clock/clock.c: The clock tick is not very precise on
at91rm9200. The attached patch improves the situation by:
(1) Not reloading the "period interval timer" register in the
interrupt handler since this is done automatically.
(2) Use integer rounding in the calculation of the "period interval
timer" register value to get as close as posible to the
CONFIGURE_MICROSECONDS_PER_TICK value.
Diffstat (limited to 'c')
| -rw-r--r-- | c/src/lib/libcpu/arm/ChangeLog | 10 | ||||
| -rw-r--r-- | c/src/lib/libcpu/arm/at91rm9200/clock/clock.c | 5 |
2 files changed, 11 insertions, 4 deletions
diff --git a/c/src/lib/libcpu/arm/ChangeLog b/c/src/lib/libcpu/arm/ChangeLog index ca9ebc86e6..cd5211cc03 100644 --- a/c/src/lib/libcpu/arm/ChangeLog +++ b/c/src/lib/libcpu/arm/ChangeLog @@ -1,3 +1,13 @@ +2006-03-07 Lars Munch <lars@segv.dk> + + * at91rm9200/clock/clock.c: The clock tick is not very precise on + at91rm9200. The attached patch improves the situation by: + (1) Not reloading the "period interval timer" register in the + interrupt handler since this is done automatically. + (2) Use integer rounding in the calculation of the "period interval + timer" register value to get as close as posible to the + CONFIGURE_MICROSECONDS_PER_TICK value. + 2005-11-04 Ralf Corsepius <ralf.corsepius@rtems.org> * configure.ac: Remove RTEMS_CHECK_CUSTOM_BSP. diff --git a/c/src/lib/libcpu/arm/at91rm9200/clock/clock.c b/c/src/lib/libcpu/arm/at91rm9200/clock/clock.c index 5bba53c101..c6876c2aa6 100644 --- a/c/src/lib/libcpu/arm/at91rm9200/clock/clock.c +++ b/c/src/lib/libcpu/arm/at91rm9200/clock/clock.c @@ -54,9 +54,6 @@ rtems_isr clock_isr(rtems_vector_number vector) /* read the status to clear the int */ st_str = ST_REG(ST_SR); - /* reload the timer value */ - ST_REG(ST_PIMR) = st_pimr_reload; - rtems_clock_tick(); } @@ -71,7 +68,7 @@ void Install_clock(rtems_isr_entry clock_isr) /* the system timer is driven from SLCK */ slck = at91rm9200_get_slck(); - st_pimr_reload = ((BSP_Configuration.microseconds_per_tick * slck) / + st_pimr_reload = (((BSP_Configuration.microseconds_per_tick * slck) + (1000000/2))/ 1000000); /* read the status to clear the int */ |