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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libbsp/] [powerpc/] [dmv177/] [timer/] [timer.c] - Blame information for rev 173

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/*  timer.c
 *
 *  This file implements a benchmark timer using the General Purpose Timer on
 *  the MEC.
 *
 *  The license and distribution terms for this file are 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 12:00:35 chris Exp $
 */
 
#include <assert.h>
 
#include <bsp.h>
 
rtems_unsigned64 Timer_driver_Start_time;
 
rtems_boolean Timer_driver_Find_average_overhead;
 
/*PAGE
 *
 *  Timer_initialize
 *
 *  This routine initializes the timer.
 *
 *  Input parameters:   NONE
 *
 *  Output parameters:  NONE
 *
 *  Return values:      NONE
 *
 */
 
void Timer_initialize()
{
  /*
   *  Timer runs long and accurate enough not to require an interrupt.
   */
 
 
  Timer_driver_Start_time = PPC_Get_timebase_register();
 
 
}
 
#define AVG_OVERHEAD     24  /* It typically takes 24 instructions */
                             /*     to start/stop the timer. */
#define LEAST_VALID       1  /* Don't trust a value lower than this */
 
/*  PAGE
 *
 *  Read_timer
 *
 *  This routine reads the timer.
 *
 *  Input parameters:   NONE
 *
 *  Output parameters:  NONE
 *
 *  Return values:      timer in ms units
 *
 */
 
int Read_timer()
{
  rtems_unsigned64  clicks;
  rtems_unsigned64  total64;
  rtems_unsigned32  total;
 
  /* approximately CLOCK_SPEED clicks per microsecond */
 
  clicks = PPC_Get_timebase_register();
 
  assert( clicks > Timer_driver_Start_time );
 
  total64 = clicks - Timer_driver_Start_time;
 
  assert( total64 <= 0xffffffff );  /* fits into a unsigned32 */
 
  total = (rtems_unsigned32) total64;
 
  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;
}
 
/*  PAGE
 *
 *  Empty_function
 *
 *  This routine is called during the idle loop.
 *
 *  Input parameters:   NONE
 *
 *  Output parameters:
 *    status code of successful
 *
 *  Return values:      NONE
 *
 */
 
rtems_status_code Empty_function( void )
{
  return RTEMS_SUCCESSFUL;
}
 
/*  PAGE
 *
 *  Set_find_average_overhead
 *
 *  This routine sets a global boolean to the value passed in.
 *
 *  Input parameters:
 *    find_flag  - flag to indicate to find the average overhead.
 *
 *  Output parameters:  NONE
 *
 *  Return values:      NONE
 *
 */
 
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.c`
2			`*`
3			`* This file implements a benchmark timer using the General Purpose Timer on`
4			`* the MEC.`
5			`*`
6			`* The license and distribution terms for this file are in`
7			`* the file LICENSE in this distribution or at`
8			`* http://www.OARcorp.com/rtems/license.html.`
9			`*`
10			`* $Id: timer.c,v 1.2 2001-09-27 12:00:35 chris Exp $`
11			`*/`
12
13			`#include <assert.h>`
14
15			`#include <bsp.h>`
16
17			`rtems_unsigned64 Timer_driver_Start_time;`
18
19			`rtems_boolean Timer_driver_Find_average_overhead;`
20
21			`/*PAGE`
22			`*`
23			`* Timer_initialize`
24			`*`
25			`* This routine initializes the timer.`
26			`*`
27			`* Input parameters: NONE`
28			`*`
29			`* Output parameters: NONE`
30			`*`
31			`* Return values: NONE`
32			`*`
33			`*/`
34
35			`void Timer_initialize()`
36			`{`
37			`/*`
38			`* Timer runs long and accurate enough not to require an interrupt.`
39			`*/`
40
41
42			`Timer_driver_Start_time = PPC_Get_timebase_register();`
43
44
45			`}`
46
47			`#define AVG_OVERHEAD 24 /* It typically takes 24 instructions */`
48			`/* to start/stop the timer. */`
49			`#define LEAST_VALID 1 /* Don't trust a value lower than this */`
50
51			`/* PAGE`
52			`*`
53			`* Read_timer`
54			`*`
55			`* This routine reads the timer.`
56			`*`
57			`* Input parameters: NONE`
58			`*`
59			`* Output parameters: NONE`
60			`*`
61			`* Return values: timer in ms units`
62			`*`
63			`*/`
64
65			`int Read_timer()`
66			`{`
67			`rtems_unsigned64 clicks;`
68			`rtems_unsigned64 total64;`
69			`rtems_unsigned32 total;`
70
71			`/* approximately CLOCK_SPEED clicks per microsecond */`
72
73			`clicks = PPC_Get_timebase_register();`
74
75			`assert( clicks > Timer_driver_Start_time );`
76
77			`total64 = clicks - Timer_driver_Start_time;`
78
79			`assert( total64 <= 0xffffffff ); /* fits into a unsigned32 */`
80
81			`total = (rtems_unsigned32) total64;`
82
83			`if ( Timer_driver_Find_average_overhead == 1 )`
84			`return total; /* in one microsecond units */`
85
86			`if ( total < LEAST_VALID )`
87			`return 0; /* below timer resolution */`
88
89			`return total - AVG_OVERHEAD;`
90			`}`
91
92			`/* PAGE`
93			`*`
94			`* Empty_function`
95			`*`
96			`* This routine is called during the idle loop.`
97			`*`
98			`* Input parameters: NONE`
99			`*`
100			`* Output parameters:`
101			`* status code of successful`
102			`*`
103			`* Return values: NONE`
104			`*`
105			`*/`
106
107			`rtems_status_code Empty_function( void )`
108			`{`
109			`return RTEMS_SUCCESSFUL;`
110			`}`
111
112			`/* PAGE`
113			`*`
114			`* Set_find_average_overhead`
115			`*`
116			`* This routine sets a global boolean to the value passed in.`
117			`*`
118			`* Input parameters:`
119			`* find_flag - flag to indicate to find the average overhead.`
120			`*`
121			`* Output parameters: NONE`
122			`*`
123			`* Return values: NONE`
124			`*`
125			`*/`
126
127			`void Set_find_average_overhead(`
128			`rtems_boolean find_flag`
129			`)`
130			`{`
131			`Timer_driver_Find_average_overhead = find_flag;`
132			`}`

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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libbsp/] [powerpc/] [dmv177/] [timer/] [timer.c] - Blame information for rev 173