0: main frequency source X
1. main and auxiliary operation
results
2:Switchover between X and Y
3:Switchover between X and main (X) &
auxiliary(Y) operation
4:Switchover between Y and main (X) &
auxiliary(Y) operation
Ten’s digit:X and Y operation relationship
0:X+Y
1:X -Y
2:Maximum
3:Minimum
4:X*Y