1 //-----------------------------------------------------
  2 // Design Name : rom_using_file
  3 // File Name   : rom_using_file.v
  4 // Function    : ROM using readmemh
  5 // Coder       : Deepak Kumar Tala
  6 //-----------------------------------------------------
  7 module rom_using_file (
  8 address , // Address input
  9 data    , // Data output
 10 read_en , // Read Enable 
 11 ce        // Chip Enable
 12 );
 13 input [7:0] address;
 14 output [7:0] data; 
 15 input read_en; 
 16 input ce; 
 17            
 18 reg [7:0] mem [0:255] ;  
 19       
 20 assign data = (ce && read_en) ? mem[address] : 8'b0;
 21 
 22 initial begin
 23   $readmemb("memory.list", mem); // memory_list is memory file
 24 end
 25 
 26 endmodule

You can find the rom model and testbench here and memory_list file here.

  1 //-----------------------------------------------------
  2 // Design Name : rom_using_case
  3 // File Name   : rom_using_case.v
  4 // Function    : ROM using case
  5 // Coder       : Deepak Kumar Tala
  6 //-----------------------------------------------------
  7 module rom_using_case (
  8 address , // Address input
  9 data    , // Data output
 10 read_en , // Read Enable 
 11 ce        // Chip Enable
 12 );
 13 input [3:0] address;
 14 output [7:0] data;
 15 input read_en;
 16 input ce;
 17 
 18 reg [7:0] data ;
 19        
 20 always @ (ce or read_en or address)
 21 begin
 22   case (address)
 23     0 : data = 10;
 24     1 : data = 55;
 25     2 : data = 244;
 26     3 : data = 0;
 27     4 : data = 1;
 28     5 : data = 8'hff;
 29     6 : data = 8'h11;
 30     7 : data = 8'h1;
 31     8 : data = 8'h10;
 32     9 : data = 8'h0;
 33     10 : data = 8'h10;
 34     11 : data = 8'h15;
 35     12 : data = 8'h60;
 36     13 : data = 8'h90;
 37     14 : data = 8'h70;
 38     15 : data = 8'h90;
 39   endcase
 40 end
 41 
 42 endmodule

Copyright © 1998-2014

Deepak Kumar Tala - All rights reserved

Do you have any Comment? mail me at:deepak@asic-world.com