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

//解题思路：L= `AC+AB=`ABC+`A`BC+ABC+AB`C
module decoder0(
   input             A     ,
   input             B     ,
   input             C     ,
   
   output wire       L
);

decoder_38 U0(
   .E1_n   (1'b0),
   .E2_n   (1'b0),
   .E3     (1'b1),
   .A0     (C),
   .A1     (B),
   .A2     (A),
   
   .Y0_n   (Y0_n),  
   .Y1_n   (Y1_n), 
   .Y2_n   (Y2_n), 
   .Y3_n   (Y3_n), 
   .Y4_n   (Y4_n), 
   .Y5_n   (Y5_n), 
   .Y6_n   (Y6_n), 
   .Y7_n   (Y7_n)
);
 
assign L = ~(Y1_n & Y3_n & Y6_n & Y7_n);

endmodule