#include <REG52.H>                /* special function register declarations   */
                                  /* for the intended 8051 derivative         */

#include <stdio.h>                /* prototype declarations for I/O functions */

#ifdef MONITOR51                         /* Debugging with Monitor-51 needs   */
char code reserve [3] _at_ 0x23;         /* space for serial interrupt if     */
#endif                                   /* Stop Exection with Serial Intr.   */
                                         /* is enabled                        */
/*------------------------------------------------
The main C function.  Program execution starts
here after stack initialization.
------------------------------------------------*/

void initial(void);

int i=0;
main()
{
	initial();
	
	while(1);
}


void initial(void)
{
	IE=0x82;              
	TCON=0x00;
	TMOD=0x00; 
	
	TH0=0xF9;
	TL0=0x18;             //
	TR1=1;                //啟動定時器0
	
}

void  TIMER(void)  interrupt 1
{
	TH0=0xB1;             
	TL0=0xE0;
	P0=P0^0x01;
	
}