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author | Ralf Corsepius <ralf.corsepius@rtems.org> | 2006-01-09 10:36:06 +0000 |
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committer | Ralf Corsepius <ralf.corsepius@rtems.org> | 2006-01-09 10:36:06 +0000 |
commit | bec7ba52314ce3beb962b6dae7131ff59ce3a76b (patch) | |
tree | d4519d9d6d802ae19767af216538fad1c5029c87 /c/src/lib/libbsp/sparc/leon2/timer/timer.c | |
parent | 2006-01-09 Ralf Corsepius <ralf.corsepius@rtems.org> (diff) | |
download | rtems-bec7ba52314ce3beb962b6dae7131ff59ce3a76b.tar.bz2 |
Backport from rtems-4-6-branch.
Diffstat (limited to 'c/src/lib/libbsp/sparc/leon2/timer/timer.c')
-rw-r--r-- | c/src/lib/libbsp/sparc/leon2/timer/timer.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/sparc/leon2/timer/timer.c b/c/src/lib/libbsp/sparc/leon2/timer/timer.c new file mode 100644 index 0000000000..0aae14362d --- /dev/null +++ b/c/src/lib/libbsp/sparc/leon2/timer/timer.c @@ -0,0 +1,83 @@ +/* timer.c + * + * This file implements a benchmark timer using timer 2. + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * Ported to LEON implementation of the SPARC by On-Line Applications + * Research Corporation (OAR) under contract to the European Space + * Agency (ESA). + * + * LEON modifications of respective RTEMS file: COPYRIGHT (c) 1995. + * European Space Agency. + * + * $Id$ + */ + + +#include <bsp.h> + +rtems_boolean Timer_driver_Find_average_overhead; + +rtems_boolean Timer_driver_Is_initialized = FALSE; + +void Timer_initialize() +{ + /* + * Timer runs long and accurate enough not to require an interrupt. + */ + + if ( Timer_driver_Is_initialized == FALSE ) { + + /* approximately 1 us per countdown */ + LEON_REG.Timer_Counter_2 = 0xffffff; + LEON_REG.Timer_Reload_2 = 0xffffff; + + } else { + Timer_driver_Is_initialized = TRUE; + } + + LEON_REG.Timer_Control_2 = ( + LEON_REG_TIMER_COUNTER_ENABLE_COUNTING | + LEON_REG_TIMER_COUNTER_LOAD_COUNTER + ); + +} + +#define AVG_OVERHEAD 3 /* It typically takes 3.0 microseconds */ + /* to start/stop the timer. */ +#define LEAST_VALID 2 /* Don't trust a value lower than this */ + +int Read_timer() +{ + rtems_unsigned32 total; + + total = LEON_REG.Timer_Counter_2; + + total = 0xffffff - total; + + if ( Timer_driver_Find_average_overhead == 1 ) + return total; /* in one microsecond units */ + + if ( total < LEAST_VALID ) + return 0; /* below timer resolution */ + + return total - AVG_OVERHEAD; +} + +rtems_status_code Empty_function( void ) +{ + return RTEMS_SUCCESSFUL; +} + +void Set_find_average_overhead( + rtems_boolean find_flag +) +{ + Timer_driver_Find_average_overhead = find_flag; +} |