Accessing individual nodes in a bus

You leave the wire CntMod4Out[0] unconnected from CntMod4Out[2..0] - the fact that you have given it the same name will connect via named association. Conneting it like your picture will probably cause an error.

Schematics are problematic for several reasons:

1. You cannot simulate them (you need to convert to HDL first)

2. You cannot easily comment them

3. They are not portable between vendors.

4. They dont play nice with version control

5. They can easily become a mess

6. They dont always map nicely to HDL, and lack a lot of the features of HDL (parameterisation being the first).

So given the above, it is usual that entire projects are done in HDL where possible, as none of the above problems apply.