NO4x is a family of 4-input gates which perform the logical NOR function. Logic Symbol Truth Table NO4x A B C Q D A B C Q D A B CDQ L L L LH HXXX L XHXX L XXHX L XXXHL Core Logic HDL Syntax Verilog NO4x inst_name (Q, A, B, C, D); VHDL inst_name: NO4x port map (Q, A, B, C, D); Pin Loa.