diff options
Diffstat (limited to 'c/src/lib/libbsp/c4x/c4xsim/timer')
| -rw-r--r-- | c/src/lib/libbsp/c4x/c4xsim/timer/Makefile.am | 32 | ||||
| -rw-r--r-- | c/src/lib/libbsp/c4x/c4xsim/timer/timer.c | 117 |
2 files changed, 149 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/c4x/c4xsim/timer/Makefile.am b/c/src/lib/libbsp/c4x/c4xsim/timer/Makefile.am new file mode 100644 index 0000000000..7f16dcc233 --- /dev/null +++ b/c/src/lib/libbsp/c4x/c4xsim/timer/Makefile.am @@ -0,0 +1,32 @@ +## +## $Id$ +## + +AUTOMAKE_OPTIONS = foreign 1.4 + +PGM = $(ARCH)/timer.rel + +C_FILES = timer.c +C_O_FILES = $(C_FILES:%.c=$(ARCH)/%.o) + +OBJS = $(C_O_FILES) + +include $(RTEMS_ROOT)/make/custom/@RTEMS_BSP@.cfg +include $(top_srcdir)/../../../../../../automake/lib.am + +# +# (OPTIONAL) Add local stuff here using += +# + +$(PGM): $(OBJS) + $(make-rel) + +# the .rel file built here will be put into libbsp.a by ../wrapup/Makefile + +all-local: $(ARCH) $(OBJS) $(PGM) + +.PRECIOUS: $(PGM) + +EXTRA_DIST = timer.c + +include $(top_srcdir)/../../../../../../automake/local.am diff --git a/c/src/lib/libbsp/c4x/c4xsim/timer/timer.c b/c/src/lib/libbsp/c4x/c4xsim/timer/timer.c new file mode 100644 index 0000000000..b32166c330 --- /dev/null +++ b/c/src/lib/libbsp/c4x/c4xsim/timer/timer.c @@ -0,0 +1,117 @@ +/* timer.c + * + * This file manages the benchmark timer used by the RTEMS Timing Test + * Suite. Each measured time period is demarcated by calls to + * Timer_initialize() and Read_timer(). Read_timer() usually returns + * the number of microseconds since Timer_initialize() exitted. + * + * NOTE: It is important that the timer start/stop overhead be + * determined when porting or modifying this code. + * + * COPYRIGHT (c) 1989-1999. + * 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.OARcorp.com/rtems/license.html. + * + * $Id$ + */ + +#include <rtems.h> +#include <bsp.h> +#include <c4xio.h> + +rtems_unsigned32 Timer_interrupts; +rtems_boolean Timer_driver_Find_average_overhead; + +static unsigned32 start; + +void Timer_initialize( void ) +{ + + /* + * Timer has never overflowed. This may not be necessary on some + * implemenations of timer but .... + */ + + + c4x_timer_stop(C4X_TIMER_0); + c4x_timer_set_period(C4X_TIMER_0, 0xffffffff); /* so no interupts */ + c4x_timer_start(C4X_TIMER_0); + start = c4x_timer_get_counter(C4X_TIMER_0); + + Timer_interrupts = 0; + + /* + * Somehow start the timer + */ +} + +/* + * The following controls the behavior of Read_timer(). + * + * AVG_OVEREHAD is the overhead for starting and stopping the timer. It + * is usually deducted from the number returned. + * + * LEAST_VALID is the lowest number this routine should trust. Numbers + * below this are "noise" and zero is returned. + */ + +#define AVG_OVERHEAD 0 /* It typically takes X.X microseconds */ + /* (Y countdowns) to start/stop the timer. */ + /* This value is in microseconds. */ +#define LEAST_VALID 1 /* Don't trust a clicks value lower than this */ + +int Read_timer( void ) +{ + rtems_unsigned32 clicks; + rtems_unsigned32 total; + int tmp; + + /* + * Read the timer and see how many clicks it has been since we started. + */ + + clicks = c4x_timer_get_counter(C4X_TIMER_0); + clicks -= start; + + /* + * Total is calculated by taking into account the number of timer overflow + * interrupts since the timer was initialized and clicks since the last + * interrupts. + */ + + total = clicks * 1; + + if ( Timer_driver_Find_average_overhead == 1 ) { + return total; /* in count units where each count is */ + /* 1 / (clock frequency/2) */ + } else { + if ( total < LEAST_VALID ) + return 0; /* below timer resolution */ + /* + * Somehow convert total into microseconds + */ + tmp = (int) ((float) total * ((1.0 / 25.0))); + return (tmp - AVG_OVERHEAD); + } +} + +/* + * Empty function call used in loops to measure basic cost of looping + * in Timing Test Suite. + */ + +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; +} + |