ENTITY buf_x8 IS GENERIC ( CONSTANT area : NATURAL := 2000; CONSTANT cin_i : NATURAL := 15; CONSTANT rdown_i_q : NATURAL := 400; CONSTANT rup_i_q : NATURAL := 450; CONSTANT tphh_i_q : NATURAL := 343; CONSTANT tpll_i_q : NATURAL := 396; CONSTANT transistors : NATURAL := 10 ); PORT ( i : in BIT; q : out BIT; vdd : in BIT; vss : in BIT ); END buf_x8; ARCHITECTURE behaviour_data_flow OF buf_x8 IS BEGIN ASSERT ((vdd and not (vss)) = '1') REPORT "power supply is missing on buf_x8" SEVERITY WARNING; q <= i after 1000 ps; END;