From cd471d6b82efdea6f83972bba67284e879111f89 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joachim=20Stro=CC=88mbergson?= <joachim@secworks.se>
Date: Thu, 12 Jun 2014 09:10:52 +0200
Subject: Update of RTL to include changes used during testing.

---
 src/rtl/coretest_bp_entropy.v |  4 ++--
 src/rtl/entropy.v             | 41 ++++++++++++++++++++++++++---------------
 src/rtl/rosc.v                |  2 +-
 3 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/src/rtl/coretest_bp_entropy.v b/src/rtl/coretest_bp_entropy.v
index bc8166a..9aaf35d 100644
--- a/src/rtl/coretest_bp_entropy.v
+++ b/src/rtl/coretest_bp_entropy.v
@@ -86,7 +86,7 @@ module coretest_bp_entropy(
   reg           ent_we;
   reg [7 : 0]   ent_address;
   reg [31 : 0]  ent_write_data;
-  wire [15 : 0] ent_read_data;
+  wire [31 : 0] ent_read_data;
   wire [7 : 0]  ent_debug;
   
   
@@ -198,7 +198,7 @@ module coretest_bp_entropy(
             ent_we             = coretest_we;
             ent_address        = coretest_address[7 : 0];
             ent_write_data     = coretest_write_data[15 : 0];
-            coretest_read_data = {16'h0000, ent_read_data};
+            coretest_read_data = ent_read_data;
             coretest_error     = 1'b0;
           end
         
diff --git a/src/rtl/entropy.v b/src/rtl/entropy.v
index 6295ef9..fed4697 100644
--- a/src/rtl/entropy.v
+++ b/src/rtl/entropy.v
@@ -43,7 +43,7 @@ module entropy(input wire          clk,
                input wire          we,
                input wire [7:0]    addr,
                input wire [15:0]   dwrite,
-               output wire [15:0]  dread,
+               output wire [31:0]  dread,
                output wire [7 : 0] debug
               );
 
@@ -61,6 +61,8 @@ module entropy(input wire          clk,
   parameter ADDR_ENT_RD_RNG1_RNG2 = 8'h10;
   parameter ADDR_ENT_RD_P         = 8'h11;
   parameter ADDR_ENT_RD_N         = 8'h12;
+  parameter ADDR_ENT_MIX          = 8'h20;
+  parameter ADDR_ENT_CONCAT       = 8'h21;
 
   
   //----------------------------------------------------------------
@@ -70,13 +72,15 @@ module entropy(input wire          clk,
   reg [31 : 0] delay_ctr_reg;  
   reg [31 : 0] delay_ctr_new;  
   reg [7 : 0]  debug_reg;
-
+  reg [31 : 0] mix_reg;
+  reg [31 : 0] concat_reg;
+ 
   
   //----------------------------------------------------------------
   // Wires.
   //----------------------------------------------------------------
-  wire [15:0] 	 p, n;
-  reg [15 : 0] tmp_dread;
+  wire [31 : 0] p, n;
+  reg [31 : 0] tmp_dread;
   
   
   //----------------------------------------------------------------
@@ -84,7 +88,7 @@ module entropy(input wire          clk,
   //----------------------------------------------------------------
   genvar i;
   generate
-    for(i=0; i<16; i=i+1) begin: tworoscs
+    for(i=0; i<32; i=i+1) begin: tworoscs
       rosc px(clk, nreset, rng1, rng2, p[i]);
       rosc nx(clk, nreset, rng1, rng2, n[i]);
     end
@@ -108,25 +112,30 @@ module entropy(input wire          clk,
 	  rng1          <= 8'h55;
 	  rng2          <= 8'haa;
           delay_ctr_reg <= 32'h00000000;
+          mix_reg       <= 32'h00000000;
+          concat_reg    <= 32'h00000000;
           debug_reg     <= 8'h00;
         end 
       else 
         begin
           delay_ctr_reg <= delay_ctr_new;
-
+          mix_reg       <= n ^ p;
+          concat_reg    <= {n[31 : 16] ^ n[15 : 0], p[31 : 16] ^ p[15 : 0]};
+          
           if (delay_ctr_reg == 32'h00000000)
             begin
               debug_reg <= n[7 : 0];
             end
           
-	  if(cs & we) begin
-	    case(addr)
-	      ADDR_ENT_WR_RNG1: rng1 <= dwrite[15:8];
-	      ADDR_ENT_WR_RNG2: rng2 <= dwrite[7:0];
-              default:;
-	    endcase
-	  end
-        end // else: !if(!nreset)
+	  if(cs & we) 
+            begin
+	      case(addr)
+	        ADDR_ENT_WR_RNG1: rng1 <= dwrite[15:8];
+	        ADDR_ENT_WR_RNG2: rng2 <= dwrite[7:0];
+                default:;
+	      endcase
+	    end
+        end
     end
 
   
@@ -139,9 +148,11 @@ module entropy(input wire          clk,
 
       if(cs & ~we)
         case(addr)
-	  ADDR_ENT_RD_RNG1_RNG2: tmp_dread = {rng1, rng2};
+	  ADDR_ENT_RD_RNG1_RNG2: tmp_dread = {16'h0000, rng1, rng2};
 	  ADDR_ENT_RD_P:         tmp_dread = p;
 	  ADDR_ENT_RD_N:         tmp_dread = n;
+	  ADDR_ENT_MIX:          tmp_dread = mix_reg;
+	  ADDR_ENT_CONCAT:       tmp_dread = concat_reg;
           default:;
          endcase
     end
diff --git a/src/rtl/rosc.v b/src/rtl/rosc.v
index 9494261..c307aa1 100644
--- a/src/rtl/rosc.v
+++ b/src/rtl/rosc.v
@@ -37,7 +37,7 @@
 //======================================================================
 
 module rosc(clk, nreset, in1, in2, dout);
-   parameter l=8;
+   parameter l=2;
    input clk, nreset;
    input [l-1:0] in1, in2;
    output reg 	 dout;
-- 
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