summaryrefslogtreecommitdiffstats
path: root/c/src/lib/libbsp/sparc/erc32/timer/timer.c
diff options
context:
space:
mode:
authorJoel Sherrill <joel.sherrill@OARcorp.com>1997-01-29 00:32:23 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>1997-01-29 00:32:23 +0000
commitcb585c31590c9bfa6675bfc7c5e04842edce0d4a (patch)
treef3e7a8cc29d39ff1d3c75ce872bcc5a64a42369c /c/src/lib/libbsp/sparc/erc32/timer/timer.c
parentMade stopping for the pause an option which can be configured in the (diff)
downloadrtems-cb585c31590c9bfa6675bfc7c5e04842edce0d4a.tar.bz2
erc32 bsp supercedes sis
Diffstat (limited to '')
-rw-r--r--c/src/lib/libbsp/sparc/erc32/timer/timer.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/sparc/erc32/timer/timer.c b/c/src/lib/libbsp/sparc/erc32/timer/timer.c
new file mode 100644
index 0000000000..bfa4482daa
--- /dev/null
+++ b/c/src/lib/libbsp/sparc/erc32/timer/timer.c
@@ -0,0 +1,89 @@
+/* timer.c
+ *
+ * This file implements a benchmark timer using the General Purpose Timer on
+ * the MEC.
+ *
+ * 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.
+ *
+ * Ported to ERC32 implementation of the SPARC by On-Line Applications
+ * Research Corporation (OAR) under contract to the European Space
+ * Agency (ESA).
+ *
+ * ERC32 modifications of respective RTEMS file: COPYRIGHT (c) 1995.
+ * European Space Agency.
+ *
+ * $Id$
+ */
+
+
+#include <bsp.h>
+
+rtems_boolean Timer_driver_Find_average_overhead;
+
+rtems_boolean Timer_driver_Is_initialized = FALSE;
+
+void Timer_initialize()
+{
+ /*
+ * Timer runs long and accurate enough not to require an interrupt.
+ */
+
+ if ( Timer_driver_Is_initialized == FALSE ) {
+
+ /* approximately 1 us per countdown */
+ ERC32_MEC.General_Purpose_Timer_Scalar = CLOCK_SPEED - 1;
+ ERC32_MEC.General_Purpose_Timer_Counter = 0xffffffff;
+
+ } else {
+ Timer_driver_Is_initialized = TRUE;
+ }
+
+ ERC32_MEC_Set_General_Purpose_Timer_Control(
+ ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING |
+ ERC32_MEC_TIMER_COUNTER_LOAD_COUNTER
+ );
+
+ ERC32_MEC_Set_General_Purpose_Timer_Control(
+ ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING
+ );
+
+}
+
+#define AVG_OVERHEAD 3 /* It typically takes 3.0 microseconds */
+ /* to start/stop the timer. */
+#define LEAST_VALID 2 /* Don't trust a value lower than this */
+
+int Read_timer()
+{
+ rtems_unsigned32 total;
+
+ total = ERC32_MEC.General_Purpose_Timer_Counter;
+
+ total = 0xffffffff - total;
+
+ 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;
+}
+
+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;
+}