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/* Timer_init()
*
* This routine is not implemented for this BSP.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* 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.rtems.com/license/LICENSE.
*
* $Id$
*/
#include <bsp.h>
bool benchmark_timer_find_average_overhead;
extern rtems_isr Clock_isr(void);
void benchmark_timer_initialize( void )
{
}
/*
* The following controls the behavior of benchmark_timer_read().
*
* FIND_AVG_OVERHEAD * instructs the routine to return the "raw" count.
*
* 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 */
/*
* Return timer value in 1/2-microsecond units
*/
int benchmark_timer_read( void )
{
uint32_t total;
total = 0;
if ( benchmark_timer_find_average_overhead == true )
return total; /* in XXX microsecond units */
if ( total < LEAST_VALID )
return 0; /* below timer resolution */
return (total - AVG_OVERHEAD);
}
void benchmark_timer_disable_subtracting_average_overhead(
bool find_flag
)
{
benchmark_timer_find_average_overhead = find_flag;
}
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