Error CMP419: The direct digital connection
at the Analog Block input <input name> is incomplete. To enable
the direct digital connection:
1. Connect Analog Block input pin to an INBUF_DA
2. Connect %en to VCC
3. Connect <output> to some FPGA logic.
You have used the Analog Block input pin incorrectly.
Action
Re-connect the Analog Block inputs to enable the digital
connection of the input pins.