diff options
author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2002-08-06 13:57:03 +0000 |
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committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2002-08-06 13:57:03 +0000 |
commit | a24d946fc0e2420a93cc80fe3965d617251df2ba (patch) | |
tree | 0b63e2efb981b29ef0d3e009c0f9f9c532e3e0dd /c/src/lib/libbsp/or32/orp/timer/timer.c | |
parent | 2002-08-06 Ralf Corsepius <corsepiu@faw.uni-ulm.de> (diff) | |
download | rtems-a24d946fc0e2420a93cc80fe3965d617251df2ba.tar.bz2 |
2002-08-06 Chris Ziomkowski <chris@asics.ws>
* .cvsignore, Makefile.am, README, bsp_specs, configure.ac, times,
clock/.cvsignore, clock/Makefile.am, clock/clockdrv.c,
console/.cvsignore, console/Makefile.am, console/console.c,
console/console.h, include/.cvsignore, include/Makefile.am,
include/bsp.h, start/.cvsignore, start/Makefile.am, start/start.S,
startup/.cvsignore, startup/bspclean.c, startup/bspstart.c,
startup/linkcmds, startup/main.c, startup/setvec.c, timer/.cvsignore,
timer/Makefile.am, timer/timer.c, timer/timerisr.c,
wrapup/.cvsignore, wrapup/Makefile.am, ChangeLog: New files added
as part of merge from OpenCores repository.
Diffstat (limited to 'c/src/lib/libbsp/or32/orp/timer/timer.c')
-rw-r--r-- | c/src/lib/libbsp/or32/orp/timer/timer.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/or32/orp/timer/timer.c b/c/src/lib/libbsp/or32/orp/timer/timer.c new file mode 100644 index 0000000000..436e44a918 --- /dev/null +++ b/c/src/lib/libbsp/or32/orp/timer/timer.c @@ -0,0 +1,104 @@ +/* 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> + +rtems_unsigned32 Timer_interrupts; +rtems_boolean Timer_driver_Find_average_overhead; + +void Timer_initialize( void ) +{ + + /* + * Timer has never overflowed. This may not be necessary on some + * implemenations of timer but .... + */ + + 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; + + /* + * Read the timer and see how many clicks it has been since we started. + */ + + clicks = 0; /* XXX: read some HW here */ + + /* + * 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 * 0; + + if ( Timer_driver_Find_average_overhead == 1 ) + return total; /* in XXX microsecond units */ + else { + if ( total < LEAST_VALID ) + return 0; /* below timer resolution */ + /* + * Somehow convert total into microseconds + */ + return (total - 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; +} + |