求助，下面的verilog代码起了什么作用。看的时候没有明白

醉月含

// leading one detector
module c_lod
  (data_in, data_out);


`include "D:/trunk/src/c_functions.v"


   // number of input ports
   parameter width = 32;


   // number of stages
   localparam depth = clogb(width);


   // vector of requests
   input [0:width-1] data_in;


   // vector of grants
   output [0:width-1] data_out;
   wire [0:width-1]   data_out;


   genvar
      level;


   wire [0:(depth+1)*width-1] a_int;
   wire [0:(depth+1)*width-1] b_int;


   assign a_int[0:width-1] = data_in;
   assign b_int[0:width-1] = data_in;


   generate


      for(level = 0; level < depth; level = level + 1)

begin:levels

   

   wire [0:width-1] a_in;

   assign a_in = a_int[level*width:(level+1)*width-1];

   

   wire [0:width-1] b_in;

   assign b_in = b_int[level*width:(level+1)*width-1];

   

   wire [0:width-1] a_shifted;

   assign a_shifted = {{(1<<level){1'b0}}, a_in[0:width-(1<<level)-1]};

   

   wire [0:width-1] a_out;

   assign a_out = a_in | a_shifted;

   

   wire [0:width-1] b_out;

   assign b_out = b_in & ~a_shifted;

   

   assign a_int[(level+1)*width:(level+2)*width-1] = a_out;

   assign b_int[(level+1)*width:(level+2)*width-1] = b_out;

   

end


   endgenerate


   assign data_out = b_int[depth*width:(depth+1)*width-1];


endmodule