AR# 40408

According to the DSP User Guide, it is possible to set AREG = 1 and use the A1 register only. Furthermore, to save power, it is possible to set CEA2 = 0.

Map:

WARNING:PhysDesignRules:2175 - Invalid configuration (incorrect pin connections

and/or modes) on block:<DSP_Slice>:<DSP48E1_DSP48E1>. When the DSP48E1 AREG
attribute is set to 1, the CEA2 input pin should have active or VCC
connectivity.

BitGen:

The user guide claims this is a valid configuration. Why are the warnings/errors occurring and how can I avoid this error?

To work around this issue in 12.x, disable DC checks in Bitgen. This can be done by using the -d switch.

Note: This disables DC errors that can potentially result in damages on the device. Use this workaround only when all Physical DC warnings in Map have been acknowledged and addressed.