#include <reg932.h> sbit sbLS1 = P0^0;                                      // Deklaration der Lichtschranke LS1 sbit sbLS2 = P0^1;                                      // Deklaration der Lichtschranke LS2 void main( void ) {     unsigned char ucZaehler = 0xFF;              // Definition der lokalen Variablen                                                                        // ucZaehler, Initialisierung mit 0xFF     P2M1 = 0x00;                                             // Port 2 als quasi-bidirektional     P2 = ucZaehler;                                 // Anzeige (Port2) = 1111 1111 (0xFF)                                                                 // 8 LEDs leuchten nicht, Kausalkette!     while(1)     {         if ( ( sbLS1 == 0 ) && ( sbLS2 == 0 ) )  // LS1 und LS2 unterbrochen?         {             ucZaehler--;             P2 = ucZaehler;             while ( sbLS2 == 0 )                            // Solange LS2 noch unterbrochen             {                 ;                                                       // Warten             }         }     } }