ENTITY zero_x0 IS GENERIC ( CONSTANT area : NATURAL := 750; CONSTANT transistors : NATURAL := 1 ); PORT ( nq : out BIT; vdd : in BIT; vss : in BIT ); END zero_x0; ARCHITECTURE behaviour_data_flow OF zero_x0 IS BEGIN ASSERT (vdd and not (vss)) REPORT "power supply is missing on zero_x0" SEVERITY WARNING; nq <= '0'; END;