如何将trie中的位置ID转换为其位置ID？ Verilog的

Question

在这个二元特里的位置ID中，左子元素占用0，右子元素占用1.因此第0级是根0，第1级是元素1和2（两个儿子是0） ），等级3是3,4（两个儿子的1），5和6（两个儿子的2）。对于位置id 6，位置id将是11.（第一个1是0的右子，第二个1是2的右子）。 我想知道在一个时钟中将位置ID（如6）转换为位置id（11）的方法是什么，或者至少更好。

例如：

6  -->  11

12 --> 101

谢谢

Answer 1

假设不支持变量输出宽度，请参阅下面的代码，它可能对您有帮助。

module find_id ( 
                 input wire [3:0] loc_id, // 1 to 14
                 output reg [2:0] pos_id
               );

reg pos_1, pos_2, pos_3;

always @ (*)
begin
  pos_1 = (loc_id == 4'd2)
        | (loc_id == 4'd5 | (loc_id == 4'd6))
        | (loc_id >= 11); 

  pos_2 = ( pos_1 & ((loc_id == 4'd6 ) | (loc_id == 4'd13 ) | (loc_id == 4'd14 )))
        | (~pos_1 & ((loc_id == 4'd4 ) | (loc_id == 4'd9  ) | (loc_id == 4'd10 )));

  pos_3 = ( pos_1 &  pos_2 & (loc_id ==  4'd14))
        | ( pos_1 & ~pos_2 & (loc_id ==  4'd12))
        | (~pos_1 &  pos_2 & (loc_id ==  4'd10))
        | (~pos_1 & ~pos_2 & (loc_id ==  4'd8 ));
end


always @ (*)
begin
  pos_id = ({3{(loc_id <= 4'd2)                    }} & {pos_1, 1'bx, 1'bx})
         | ({3{(loc_id <= 4'd6)  & (loc_id >= 4'd3)}} & {pos_1,pos_2, 1'bx})
         | ({3{(loc_id <= 4'd14) & (loc_id >= 4'd7)}} & {pos_1,pos_2,pos_3}) ;
end

endmodule

有关验证，请参阅TB：

module tb;

reg [3:0] loc_id;
wire [2:0] pos_id;

find_id find_id_0(loc_id,  pos_id);

initial
begin
  loc_id = 4'b0;
  #100 loc_id = 4'd10;
  #100 loc_id = 4'd9;
  #100 loc_id = 4'd13;
  #100 loc_id = 4'd6;
  #100 loc_id = 4'd8;
  #100 loc_id = 4'd11;
  #100 loc_id = 4'd7;
  #100 loc_id = 4'd4;
  #100 loc_id = 4'd12;
  #100 $finish;
end

initial
  $monitor ("loc_id = %d pos_id =%b",loc_id, pos_id);

endmodule

模拟结果之后会是这样的：

# 10.4

# vsim -lib work tb -c -do "run -all; quit -f" -appendlog -l qverilog.log -vopt 
# ** Note: (vsim-3813) Design is being optimized due to module recompilation...
# //  Questa Sim-64
# //  Version 10.4 linux_x86_64 Dec  2 2014
# //
# //  Copyright 1991-2014 Mentor Graphics Corporation
# //  All Rights Reserved.
# //
# //  THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION
# //  WHICH IS THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS
# //  LICENSORS AND IS SUBJECT TO LICENSE TERMS.
# //  THIS DOCUMENT CONTAINS TRADE SECRETS AND COMMERCIAL OR FINANCIAL
# //  INFORMATION THAT ARE PRIVILEGED, CONFIDENTIAL, AND EXEMPT FROM
# //  DISCLOSURE UNDER THE FREEDOM OF INFORMATION ACT, 5 U.S.C. SECTION 552.
# //  FURTHERMORE, THIS INFORMATION IS PROHIBITED FROM DISCLOSURE UNDER
# //  THE TRADE SECRETS ACT, 18 U.S.C. SECTION 1905.
# //
# Loading work.tb(fast)
# run -all
# loc_id =  0 pos_id =0xx
# loc_id = 10 pos_id =011
# loc_id =  9 pos_id =010
# loc_id = 13 pos_id =110
# loc_id =  6 pos_id =11x
# loc_id =  8 pos_id =001
# loc_id = 11 pos_id =100
# loc_id =  7 pos_id =000
# loc_id =  4 pos_id =01x
# loc_id = 12 pos_id =101
# ** Note: $finish    : find_id.v(56)
#    Time: 1 us  Iteration: 0  Instance: /tb
# End time: 09:58:04 on May 18,2016, Elapsed time: 0:00:01
# Errors: 0, Warnings: 0