题解 | #使用3-8译码器①实现逻辑函数#

`timescale 1ns/1ns

module decoder_38(
   input             E1_n   ,
   input             E2_n   ,
   input             E3     ,
   input             A0     ,
   input             A1     ,
   input             A2     ,
   
   output wire       Y0_n   ,  
   output wire       Y1_n   , 
   output wire       Y2_n   , 
   output wire       Y3_n   , 
   output wire       Y4_n   , 
   output wire       Y5_n   , 
   output wire       Y6_n   , 
   output wire       Y7_n   
);
wire E ;
assign E = E3 & ~E2_n & ~E1_n;
assign  Y0_n = ~(E & ~A2 & ~A1 & ~A0);
assign  Y1_n = ~(E & ~A2 & ~A1 &  A0);
assign  Y2_n = ~(E & ~A2 &  A1 & ~A0);
assign  Y3_n = ~(E & ~A2 &  A1 &  A0);
assign  Y4_n = ~(E &  A2 & ~A1 & ~A0);
assign  Y5_n = ~(E &  A2 & ~A1 &  A0);
assign  Y6_n = ~(E &  A2 &  A1 & ~A0);
assign  Y7_n = ~(E &  A2 &  A1 &  A0);
     
endmodule

module decoder0(
   input             A     ,
   input             B     ,
   input             C     ,
   
   output wire       L
);

wire [7:0] Y_n;

assign L = !Y_n[1] | !Y_n[3] | !Y_n[6] | !Y_n[7];

decoder_38 decoder_38_u(
    // input
    .E1_n   (1'b0),
    .E2_n   (1'b0),
    .E3     (1'b1),
    .A0     (C),
    .A1     (B),
    .A2     (A),
    // output
    .Y0_n   (Y_n[0]),  
    .Y1_n   (Y_n[1]), 
    .Y2_n   (Y_n[2]), 
    .Y3_n   (Y_n[3]), 
    .Y4_n   (Y_n[4]), 
    .Y5_n   (Y_n[5]), 
    .Y6_n   (Y_n[6]), 
    .Y7_n   (Y_n[7])
);

endmodule