1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/*
* 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>
#include <rtems/zilog/z8036.h>
#define TIMER 0xfffb0000 /* address of Z8036 on MVME136 */
int Ttimer_val;
bool benchmark_timer_find_average_overhead;
rtems_isr timerisr(void);
void benchmark_timer_initialize(void)
{
(void) set_vector( timerisr, 66, 0 ); /* install ISR */
Ttimer_val = 0; /* clear timer ISR count */
Z8x36_WRITE( TIMER, MASTER_INTR, 0x01 ); /* reset */
Z8x36_WRITE( TIMER, MASTER_INTR, 0x00 ); /* clear reset */
Z8x36_WRITE( TIMER, MASTER_INTR, 0xe2 ); /* disable lower chain, no vec */
/* set right justified addr */
/* and master int enable */
Z8x36_WRITE( TIMER, CT1_MODE_SPEC, 0x80 ); /* T1 continuous, and */
/* cycle/pulse output */
*((uint16_t*)0xfffb0016) = 0x0000; /* write countdown value */
/*
Z8x36_WRITE( TIMER, CT1_TIME_CONST_MSB, 0x00 );
Z8x36_WRITE( TIMER, CT1_TIME_CONST_LSB, 0x00 );
*/
Z8x36_WRITE( TIMER, MASTER_CFG, 0xc4 ); /* enable timer1 */
Z8x36_WRITE( TIMER, CT1_CMD_STATUS, 0xc6 ); /* set INTR enable (IE), */
/* trigger command */
/* (TCB) and gate */
/* command (GCB) bits */
*((uint8_t*)0xfffb0038) &= 0xfd; /* enable timer INTR on */
/* VME controller */
}
#define AVG_OVERHEAD 6 /* It typically takes 3.0 microseconds */
/* (6 countdowns) to start/stop the timer. */
#define LEAST_VALID 10 /* Don't trust a value lower than this */
int benchmark_timer_read(void)
{
/*
uint8_t msb, lsb;
*/
uint32_t remaining, total;
Z8x36_WRITE( TIMER, CT1_CMD_STATUS, 0xce ); /* read the counter value */
remaining = 0xffff - *((uint16_t*) 0xfffb0010);
/*
Z8x36_READ( TIMER, CT1_CUR_CNT_MSB, msb );
Z8x36_READ( TIMER, CT1_CUR_CNT_LSB, lsb );
remaining = 0xffff - ((msb << 8) + lsb);
*/
total = (Ttimer_val * 0x10000) + remaining;
if ( benchmark_timer_find_average_overhead == true )
return total; /* in one-half microsecond units */
else {
if ( total < LEAST_VALID )
return 0; /* below timer resolution */
return (total-AVG_OVERHEAD) >> 1;
}
}
void benchmark_timer_disable_subtracting_average_overhead(
bool find_flag
)
{
benchmark_timer_find_average_overhead = find_flag;
}
|
