From ac7d5ef06a6d6e8d84abbd1f0b82162725f98326 Mon Sep 17 00:00:00 2001
From: Joel Sherrill <joel.sherrill@OARcorp.com>
Date: Thu, 11 May 1995 17:39:37 +0000
Subject: Initial revision

---
 c/src/lib/libbsp/m68k/mvme162/timer/timer.c | 91 +++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 c/src/lib/libbsp/m68k/mvme162/timer/timer.c

(limited to 'c/src/lib/libbsp/m68k/mvme162/timer/timer.c')

diff --git a/c/src/lib/libbsp/m68k/mvme162/timer/timer.c b/c/src/lib/libbsp/m68k/mvme162/timer/timer.c
new file mode 100644
index 0000000000..c000fadd28
--- /dev/null
+++ b/c/src/lib/libbsp/m68k/mvme162/timer/timer.c
@@ -0,0 +1,91 @@
+/*  Timer_init()
+ *
+ *  This routine initializes the Tick Timer 1 on the MVME162 board.
+ *
+ *  Input parameters:  NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  NOTE: This routine will not work if the optimizer is enabled
+ *        for some compilers.  The multiple writes
+ *        may be optimized away.
+ *
+ *        It is important that the timer start/stop overhead be
+ *        determined when porting or modifying this code.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  Modifications of respective RTEMS file: COPYRIGHT (c) 1994.
+ *  EISCAT Scientific Association. M.Savitski
+ *
+ *  This material is a part of the MVME162 Board Support Package
+ *  for the RTEMS executive. Its licensing policies are those of the
+ *  RTEMS above.
+ *
+ *  $Id$
+ */
+
+
+#include <rtems.h>
+#include <bsp.h>
+
+/* Periodic tick interval */
+#define TICK_INTERVAL                                   0x10000
+#define TIMER_INT_LEVEL                         6
+
+int Ttimer_val;
+rtems_boolean Timer_driver_Find_average_overhead;
+
+rtems_isr timerisr();
+
+void Timer_initialize()
+{
+  (void) set_vector( timerisr, (VECTOR_BASE >> 28) * 0x10 + 0x8, 0 );
+
+  Ttimer_val = 0;                                    /* clear timer ISR count */
+  lcsr->vector_base = 0x67800000;                /* set vb, enable interrupts */
+  lcsr->to_ctl = 0xE7;                /* prescaler to 1 MHz (see Appendix A1) */
+  lcsr->timer_cmp_1 = TICK_INTERVAL;
+  lcsr->timer_cnt_1 = 0;                                     /* clear counter */
+  lcsr->board_ctl |= 7;        /* increment, reset-on-compare, clear-ovfl-cnt */
+
+  lcsr->intr_level[0] |= TIMER_INT_LEVEL;                    /* set int level */
+  lcsr->intr_ena |= 0x01000000;              /* enable tick timer 1 interrupt */
+}
+
+#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 Read_timer()
+{
+  unsigned long                 total;
+
+  total = (Ttimer_val * TICK_INTERVAL) + lcsr->timer_cnt_1;
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+    return total;          /* in one-half microsecond units */
+
+  if ( total < LEAST_VALID )
+    return 0;            /* below timer resolution */
+
+  return (total-AVG_OVERHEAD);                  /* in musec units */
+}
+
+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;
+}
-- 
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