Turbo C 3.0 + UCOS2 + UCGUI PC学习版本

				/*------------------------------------------------------------------------*/
				/*                                                                        */
				/*  TIMER.CPP                                                             */
				/*                                                                        */
				/*  Copyright Borland International 1991                                  */
				/*  All Rights Reserved                                                   */
				/*                                                                        */
				/*------------------------------------------------------------------------*/
				
				#if !defined( __TIMER_H )
				#include 
				#endif  // __TIMER_H
				
				#if !defined( __DOS_H )
				#include 
				#endif  // __DOS_H
				
				const unsigned long far * const dosTime =
				    (const unsigned long far * const)MK_FP( 0x40, 0x6C );
				
				unsigned Timer::adjust = calibrate();
				
				Timer::Timer() : time_(0), running(0)
				{
				}
				
				void Timer::start()
				{
				    if( !running )
				        {
				        outportb( 0x43, 0x34 );
				        asm jmp __1;
				    __1:
				        outportb( 0x40, 0 );
				        asm jmp __2;
				    __2:
				        outportb( 0x40, 0 );
				        startTime.dosCount = *dosTime;
				        startTime.timerCount = 0;
				        running = 1;
				        }
				}
				
				void Timer::stop()
				{
				    outportb( 0x43, 0 );
				    unsigned char temp = inportb( 0x40 );
				
				    TIME stopTime;
				    stopTime.timerCount = (inportb( 0x40 ) 				    stopTime.dosCount = *dosTime;
				
				    TIME elapsedTime;
				    elapsedTime.dosCount = stopTime.dosCount - startTime.dosCount;
				    elapsedTime.timerCount = -( stopTime.timerCount - adjust );
				
				    const double fudge = 83810.0/100000.0;
				    time_ += ((elapsedTime.dosCount 				
				    running = 0;
				
				}
				
				void Timer::reset()
				{
				    time_ = 0;
				    if( running )
				        start();
				}
				
				unsigned Timer::calibrate()
				{
				    adjust = 0;
				    unsigned long sum = 0;
				    Timer w;
				    for( int i = 0; i < 100; i++ )
				        {
				        w.start();
				        w.stop();
				        sum += w.time();
				        w.reset();
				        }
				    return (unsigned)((sum+5)/100);
				}
				
				#if defined( TEST_TIMER )
				#include 
				#include 
				
				int main( void )
				{
				    delay( 0 );
				    cout 				    Timer w;
				    for( unsigned del = 0; del < 10; del++ )
				        {
				        unsigned d1 = del*100;
				        w.start();
				        delay( d1 );
				        w.stop();
				        printf( "%4u ms., actual time = %6f seconds.\n", d1, w.time() );
				        w.reset();
				        }
				    return 0;
				}
				#endif /* TEST_TIMER */