ID:17954 Can't synthesize exponentiation operator "**" with non-constant operands (filename: "<name>", line: <number>). Change your design to remove the exponentiation operator.
CAUSE: In the specified file you used a ** operator with non-constant operands. However, the Quartus Prime software cannot synthesize exponentiation operators with non-constant operands.
ACTION: Change your design to remove the exponentiation operator.