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times reported reasonably correctly

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This commit is contained in:
Joel Sherrill
1995-07-24 15:43:17 +00:00
parent 2f2a597c73
commit c35e962218
1 changed files with 5 additions and 4 deletions
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9
c/src/lib/libbsp/i386/go32/timer/timer.c
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@@ -35,6 +35,7 @@ static inline unsigned long long rdtsc( void )
return result; return result;
} }
#else #else
#define US_PER_ISR 250
extern rtems_isr timerisr(); extern rtems_isr timerisr();
static rtems_isr_entry Old_Ticker; static rtems_isr_entry Old_Ticker;
#endif #endif
@@ -83,10 +84,10 @@ void Timer_initialize()
while ( Ttimer_val == 0 ) while ( Ttimer_val == 0 )
continue; continue;
/* load timer for 250 microsecond period */ /* load timer for US_PER_ISR microsecond period */
outport_byte( TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN ); outport_byte( TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN );
outport_byte( TIMER_CNTR0, US_TO_TICK(250) >> 0 & 0xff ); outport_byte( TIMER_CNTR0, US_TO_TICK(US_PER_ISR) >> 0 & 0xff );
outport_byte( TIMER_CNTR0, US_TO_TICK(250) >> 8 & 0xff ); outport_byte( TIMER_CNTR0, US_TO_TICK(US_PER_ISR) >> 8 & 0xff );
#endif /* PENTIUM */ #endif /* PENTIUM */
} }
#if defined(pentium) #if defined(pentium)
@@ -117,7 +118,7 @@ int Read_timer()
inport_byte( TIMER_CNTR0, lsb ); inport_byte( TIMER_CNTR0, lsb );
inport_byte( TIMER_CNTR0, msb ); inport_byte( TIMER_CNTR0, msb );
clicks = msb << 8 | lsb; clicks = msb << 8 | lsb;
total = Ttimer_val + 250 - TICK_TO_US( clicks ); total = (Ttimer_val * US_PER_ISR) + (US_PER_ISR - TICK_TO_US( clicks ));
#endif /* pentium */ #endif /* pentium */
if ( Timer_driver_Find_average_overhead == 1 ) if ( Timer_driver_Find_average_overhead == 1 )