#使用8线-3线优先编码器Ⅰ实现16线-4线优先编码器#

`timescale 1ns/1ns
module encoder_83(
   input      [7:0]       I   ,
   input                  EI  ,
   
   output wire [2:0]      Y   ,
   output wire            GS  ,
   output wire            EO    
);
assign Y[2] = EI & (I[7] | I[6] | I[5] | I[4]);
assign Y[1] = EI & (I[7] | I[6] | ~I[5]&~I[4]&I[3] | ~I[5]&~I[4]&I[2]);
assign Y[0] = EI & (I[7] | ~I[6]&I[5] | ~I[6]&~I[4]&I[3] | ~I[6]&~I[4]&~I[2]&I[1]);

assign EO = EI&~I[7]&~I[6]&~I[5]&~I[4]&~I[3]&~I[2]&~I[1]&~I[0];

assign GS = EI&(I[7] | I[6] | I[5] | I[4] | I[3] | I[2] | I[1] | I[0]);
//assign GS = EI&(| I);
         
endmodule

module encoder_164(
   input      [15:0]      A   ,
   input                  EI  ,
   
   output wire [3:0]      L   ,
   output wire            GS  ,
   output wire            EO    
);

wire    [2:0]   Y_h,Y_l;
wand            eo;
wire            gs_h,gs_l;

assign  L[2:0] = Y_h | ((~{3{gs_h}}) & Y_l);
assign  L[3] = gs_h;
assign  EO = eo;
assign  GS = gs_h | gs_l;

encoder_83 inst_hB
(
   .I   (A[15:8]),
   .EI  (EI     ),
   
   .Y   (Y_h   ),
   .GS  (gs_h   ),
   .EO  (eo     )  
);

encoder_83 inst_lB
(
   .I   (A[7:0] ),
   .EI  (EI     ),
   
   .Y   (Y_l   ),
   .GS  (gs_l   ),
   .EO  (eo     )  
);

endmodule