Hi, you need to do some decimal to binary conversion
D= Bin
0= 0000 all PORT pins set to 0
1= 0001 only PORT.0 is set
2= 0010 only PORT.1 is set
3= 0011 PORT.0 and PORT.1 are set
4= 0100
5= 0101
6= 0110
7= 0111
8= 1000
and so on