This document says that I should "Connection1: In this case, both Vccd pins should be connected together with shortest possible route on the PCB, preferably under the PSoC chip."
but I mistakenly didn't make a PCB route shorted Vccd1 and Vccd2 together. My project work now without shorted Vccd1:Vccd2
What is this fraught with ? can this affect EMC immunity?
If Vccd1 and Vccd2 are not shorted it may or may not effect the EMC immunity.
Following the hardware guidelines will ensure better EMC immunity.
Please go through the hardware design guidelines in the below link