From cb585c31590c9bfa6675bfc7c5e04842edce0d4a Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Wed, 29 Jan 1997 00:32:23 +0000 Subject: erc32 bsp supercedes sis --- c/src/lib/libbsp/sparc/erc32/timer/timer.c | 89 ++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 c/src/lib/libbsp/sparc/erc32/timer/timer.c (limited to 'c/src/lib/libbsp/sparc/erc32/timer/timer.c') 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 + +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; +} -- cgit v1.2.3