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/*  Timer_init()
 *
 *  This routine initializes a timer in efi68k's DP8570A TCP
 *
 *  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.OARcorp.com/rtems/license.html.
 *
 *  $Id: timer.c,v 1.2 2001-09-27 12:00:02 chris Exp $
 */
 
 
#include <bsp.h>
 
rtems_boolean Timer_driver_Find_average_overhead;
 
extern rtems_isr Clock_isr();
 
void Timer_initialize( void )
{
}
 
/*
 *  The following controls the behavior of Read_timer().
 *
 *  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 Read_timer( void )
{
  rtems_unsigned32 total;
  total = 0;
 
  if ( Timer_driver_Find_average_overhead == 1 )
    return total;          /* in XXX microsecond units */
 
  if ( total < LEAST_VALID )
    return 0;            /* below timer resolution */
 
  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;
}

Line No.	Rev	Author	Line
1	30	unneback	`/* Timer_init()`
2			`*`
3			`* This routine initializes a timer in efi68k's DP8570A TCP`
4			`*`
5			`* Input parameters: NONE`
6			`*`
7			`* Output parameters: NONE`
8			`*`
9			`* NOTE: It is important that the timer start/stop overhead be`
10			`* determined when porting or modifying this code.`
11			`*`
12			`* COPYRIGHT (c) 1989-1999.`
13			`* On-Line Applications Research Corporation (OAR).`
14			`*`
15			`* The license and distribution terms for this file may be`
16			`* found in the file LICENSE in this distribution or at`
17			`* http://www.OARcorp.com/rtems/license.html.`
18			`*`
19			`* $Id: timer.c,v 1.2 2001-09-27 12:00:02 chris Exp $`
20			`*/`
21
22
23			`#include <bsp.h>`
24
25			`rtems_boolean Timer_driver_Find_average_overhead;`
26
27			`extern rtems_isr Clock_isr();`
28
29			`void Timer_initialize( void )`
30			`{`
31			`}`
32
33			`/*`
34			`* The following controls the behavior of Read_timer().`
35			`*`
36			`* FIND_AVG_OVERHEAD * instructs the routine to return the "raw" count.`
37			`*`
38			`* AVG_OVEREHAD is the overhead for starting and stopping the timer. It`
39			`* is usually deducted from the number returned.`
40			`*`
41			`* LEAST_VALID is the lowest number this routine should trust. Numbers`
42			`* below this are "noise" and zero is returned.`
43			`*/`
44
45			`#define AVG_OVERHEAD 0 /* It typically takes X.X microseconds */`
46			`/* (Y countdowns) to start/stop the timer. */`
47			`/* This value is in microseconds. */`
48			`#define LEAST_VALID 1 /* Don't trust a clicks value lower than this */`
49
50			`/*`
51			`* Return timer value in 1/2-microsecond units`
52			`*/`
53			`int Read_timer( void )`
54			`{`
55			`rtems_unsigned32 total;`
56			`total = 0;`
57
58			`if ( Timer_driver_Find_average_overhead == 1 )`
59			`return total; /* in XXX microsecond units */`
60
61			`if ( total < LEAST_VALID )`
62			`return 0; /* below timer resolution */`
63
64			`return (total - AVG_OVERHEAD);`
65			`}`
66
67
68			`/*`
69			`* Empty function call used in loops to measure basic cost of looping`
70			`* in Timing Test Suite.`
71			`*/`
72
73			`rtems_status_code Empty_function(void)`
74			`{`
75			`return RTEMS_SUCCESSFUL;`
76			`}`
77
78			`void Set_find_average_overhead(`
79			`rtems_boolean find_flag`
80			`)`
81			`{`
82			`Timer_driver_Find_average_overhead = find_flag;`
83			`}`

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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libbsp/] [m68k/] [efi332/] [timer/] [timer.c] - Blame information for rev 239