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2000-12-19 Joel Sherrill <joel@OARcorp.com>

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* timer: New subdirectory.
	* timer/.cvsignore, timer/Makefile.am, timer/timer.c: New files.
	* tools/ChangeLog: New file.
This commit is contained in:
Joel Sherrill
2000-12-19 16:54:36 +00:00
parent 2ba9d3bdcc
commit 8f81248cb7
5 changed files with 118 additions and 0 deletions
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74
c/src/lib/libbsp/mips/jmr3904/timer/timer.c Normal file
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/*
* This file implements a benchmark timer using a TX39 timer.
*
* NOTE: On the simulator, the count directly reflects instructions.
*
* COPYRIGHT (c) 1989-2000.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#include <assert.h>
#include <bsp.h>
rtems_boolean Timer_driver_Find_average_overhead;
void Timer_initialize()
{
/*
* Programming the compare register as the maximum value should let
* it run long enough and accurate enough not to require an interrupt.
* but if it ever does generate an interrupt, we will simply fault.
*
* NOTE: This is identical to the clock driver initialization
* with the exception that the divider is disabled and
* the compare register is set to the maximum value.
*/
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_CCDR, 0x3 );
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_TRR, 0x0 );
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_CPRA, 0xFFFFFFFF );
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_TISR, 0x00 );
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_ITMR, 0x8001 );
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_TCR, 0xc0 );
*((volatile unsigned32 *) 0xFFFFC01C) = 0x00000700;
}
#define AVG_OVERHEAD 0 /* It typically takes 24 instructions */
/* to start/stop the timer. */
#define LEAST_VALID 1 /* Don't trust a value lower than this */
/* tx39 simulator can count instructions. :) */
int Read_timer()
{
rtems_unsigned32 total;
TX3904_TIMER_WRITE( TX3904_TIMER0_BASE, TX3904_TIMER_TCR, 0x03 );
total = TX3904_TIMER_READ( TX3904_TIMER0_BASE, TX3904_TIMER_TRR );
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;
}