/* 2013/11/11 By M.kikuchi
   ATTiny13A 1.2MHz     PWM
   PORTB0 OC1A          Config H=1F  L=6A
   ROM   174 bytes
*/
char  Temp,lp;

void  WA1(char W_ct){    
//                           Wct=0までのループ
      do{
        W_ct--;
      }while(W_ct != 0);
}

void MY_PWM(char MY_P){　　　　　　　// time of loop 1.31*10= 13.1mSec
     if (my_p==0) my_p=1;
     TEMP=0;
     for (TEMP=0;TEMP <10;TEMP++){
         PORTB0_bit=1;
         WA1(MY_P);
         PORTB0_bit=0;
         WA1(255-MY_P);
     }
}

void main() {
//
     DDRB = 0b00000001;      //
     PORTB= 0b00000100;

     while(1){               // 13mS
        for (lp=1;lp<255;lp+=2){
           MY_PWM(lp);
        }
      }
}