aboutsummaryrefslogtreecommitdiffstats
path: root/tests/asicworld/code_hdl_models_cam.v
blob: 0cebc07ccb3c0a4b2c7913ebff4d47d9fddef66b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
//-----------------------------------------------------
// Design Name : cam
// File Name   : cam.v
// Function    : CAM
// Coder       : Deepak Kumar Tala
//-----------------------------------------------------
module cam (
clk         , // Cam clock
cam_enable  , // Cam enable
cam_data_in , // Cam data to match
cam_hit_out , // Cam match has happened
cam_addr_out  // Cam output address 
);

parameter ADDR_WIDTH  = 8;
parameter DEPTH       = 1 << ADDR_WIDTH;
//------------Input Ports--------------
input                    clk;      
input                    cam_enable;   
input  [DEPTH-1:0]       cam_data_in;  
//----------Output Ports--------------
output                   cam_hit_out;  
output [ADDR_WIDTH-1:0]  cam_addr_out;  
//------------Internal Variables--------
reg [ADDR_WIDTH-1:0]  cam_addr_out;
reg                   cam_hit_out;
reg [ADDR_WIDTH-1:0]  cam_addr_combo;
reg                   cam_hit_combo;
reg                   found_match;
integer               i;
//-------------Code Starts Here-------
always @(cam_data_in) begin
  cam_addr_combo   = {ADDR_WIDTH{1'b0}};
  found_match      = 1'b0;
  cam_hit_combo    = 1'b0;
  for (i=0; i<DEPTH; i=i+1) begin
    if (cam_data_in[i] && !found_match) begin
      found_match     = 1'b1;
      cam_hit_combo   = 1'b1;
      cam_addr_combo  = i;
    end else begin
      found_match     = found_match;
      cam_hit_combo   = cam_hit_combo;
      cam_addr_combo  = cam_addr_combo;
    end
  end
end

// Register the outputs 
always @(posedge clk) begin
  if (cam_enable) begin
    cam_hit_out  <=  cam_hit_combo;
    cam_addr_out <=  cam_addr_combo;
  end else begin
    cam_hit_out  <=  1'b0;
    cam_addr_out <=  {ADDR_WIDTH{1'b0}};
  end
end

endmodule