To me, if you are using unregulated external power supply connecting VCCD and VDD does not seem to be correct.
If you are providing regulated power it will be fine.
(See Page 6 and 7 of following AN)
I'd suggest you to download "PSoC Hardware Design Considerations - AN88619" and review it.
At the last part of the AN, there is an Appendix-C which is "Schematic Checklist".