source: rtems/c/src/lib/libbsp/i960/rxgen960/timer/timer.c @ 1fc3537

4.104.114.84.9
Last change on this file since 1fc3537 was 1fc3537, checked in by Joel Sherrill <joel.sherrill@…>, on Oct 12, 2001 at 9:07:45 PM

2001-10-12 Joel Sherrill <joel@…>

  • clock/ckinit.c, console/console.c, include/bsp.h, startup/bspstart.c, startup/exit.c, startup/setvec.c, timer/timer.c, timer/timerisr.S: Fixed typo.
  • Property mode set to 100644
File size: 3.3 KB
Line 
1/*  Timer_init()
2 *
3 *  This routine initializes the Z8536 timer on the SQSIO4 SQUALL
4 *  board for the CVME961 board.  The timer is setup to provide a
5 *  tick every 1 millisecond.
6 *
7 *  Input parameters:  NONE
8 *
9 *  Output parameters:  NONE
10 *
11 *  NOTE: This routine will not work if the optimizer is enabled
12 *        for most compilers.  The multiple writes to the Z8536
13 *        will be optimized away.
14 *
15 *        It is important that the timer start/stop overhead be
16 *        determined when porting or modifying this code.
17 *
18 *  COPYRIGHT (c) 1989-1997.
19 *  On-Line Applications Research Corporation (OAR).
20 *
21 *  The license and distribution terms for this file may in
22 *  the file LICENSE in this distribution or at
23 *  http://www.OARcorp.com/rtems/license.html.
24 *
25 *  $Id$
26 */
27
28
29#include <bsp.h>
30#include <stdlib.h>
31#include <rtems/libio.h>
32
33
34#define TIMER_VECTOR 34
35
36int Ttimer_val;
37rtems_boolean Timer_driver_Find_average_overhead = 0;
38
39void flush_reg();
40rtems_isr timerisr();
41
42void Timer_initialize()
43{
44  volatile unsigned int *tmr1 = (unsigned int *) TMR1_ADDR;
45  volatile unsigned int *trr1 = (unsigned int *) TRR1_ADDR;
46  volatile unsigned int *tcr1 = (unsigned int *) TCR1_ADDR;
47  volatile unsigned int *imsk = (unsigned int *) IMSK_ADDR;
48  volatile unsigned int *icon = (unsigned int *) ICON_ADDR;
49  volatile unsigned int *ipnd = (unsigned int *) IPND_ADDR;
50  volatile unsigned int *imap2 = (unsigned int *) IMAP2_ADDR;
51
52    #define BUS_CLOCK_1 0
53    #define TMR_WRITE_CNTL 8
54    #define TMR_AUTO_RELOAD 4
55    #define TMR_ENABLE 2
56    #define TMR_TERM_CNT_STAT 1
57 
58    *tmr1 = BUS_CLOCK_1 | TMR_AUTO_RELOAD; 
59     *icon = 0x6000; 
60
61
62    set_vector( (((unsigned int) timerisr) | 0x2), TIMER_VECTOR, 1 );
63
64    *imap2 = (*imap2 & 0xff0fffff) | (((TIMER_VECTOR >> 4) & 0xf) << 20);
65
66    /* initialize the i960RP timer 1 here */
67   
68    /* set the timer countdown */
69    *trr1 = 33 * BSP_Configuration.microseconds_per_tick;
70    *tcr1 = 33 * BSP_Configuration.microseconds_per_tick;
71 
72    *ipnd &= ~(1<<13);
73    *imsk |= (1 << 13); 
74    Ttimer_val = 0;
75    *tmr1 = BUS_CLOCK_1 | TMR_AUTO_RELOAD | TMR_ENABLE;
76
77}
78
79
80
81rtems_isr timerisr(
82  rtems_vector_number vector
83)
84{
85  /* enable_tracing(); */
86  Ttimer_val++;
87  i960_clear_intr( 13 );
88}
89
90#define AVG_OVERHEAD      4 /* It typically takes 5.5 microseconds */
91                             /* (11 countdowns) to start/stop the timer. */
92#define LEAST_VALID       5 /* Don't trust a value lower than this */
93
94int Read_timer()
95{
96  volatile unsigned int *tcr1 = (unsigned int *) TCR1_ADDR;
97  volatile unsigned int *trr1 = (unsigned int *) TRR1_ADDR;
98  rtems_unsigned32 remaining, total;
99
100  /* this routine is supposed to count in 1/2 uSec units */
101  /* pretty funny when using a 33MHz clock for the counter */
102  remaining =  *tcr1;
103  remaining =  *trr1 - remaining;
104  total = (2 * ((Ttimer_val * *trr1) + remaining)) / 33;
105/*
106  putnum(remaining);
107  console_sps_putc(':');
108  putnum(total);
109*/
110
111  if ( Timer_driver_Find_average_overhead == 1 )
112    return total;          /* in one-half microsecond units */
113  else {
114    if ( total < LEAST_VALID )
115      return 0;            /* below timer resolution */
116    return (total-AVG_OVERHEAD) >> 1;
117  }
118}
119
120rtems_status_code Empty_function( void )
121{
122  return RTEMS_SUCCESSFUL;
123}
124
125void Set_find_average_overhead(
126  rtems_boolean find_flag
127)
128{
129  Timer_driver_Find_average_overhead = find_flag;
130}
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