Reverse FOR..LOOP in PL/SQL

Normal For Loop:
FOR k IN 1..500 LOOP
p := p + 1;
END LOOP;

Reverse For Loop:
BEGIN
FOR i IN REVERSE 1..3 LOOP -- assign the values 1,2,3 to i
DBMS_OUTPUT.PUT_LINE (TO_CHAR(i));
END LOOP;
END;
/