Hard coded the connections between the trng and the i2c to remove the address multiplexer. This now builds a novena FPGA design with what seems to be a working trng.

2 files changed, 64 insertions, 56 deletions

diff --git a/src/rtl/coretest_trng.v b/src/rtl/coretest_trng.v
index a935f4e..17bb34c 100644
--- a/src/rtl/coretest_trng.v
+++ b/src/rtl/coretest_trng.v
@@ -58,7 +58,7 @@ module coretest_trng(
   // Internal constant and parameter definitions.
   //----------------------------------------------------------------
   parameter I2C_ADDR_PREFIX  = 4'h0;
-  parameter TRNG_ADDR_PREFIX = 4'h2;
+  parameter TRNG_ADDR_PREFIX = 4'h1;
 
 
   //----------------------------------------------------------------
@@ -70,8 +70,8 @@ module coretest_trng(
   wire          coretest_we;
   wire [15 : 0] coretest_address;
   wire [31 : 0] coretest_write_data;
-  reg [31 : 0]  coretest_read_data;
-  reg           coretest_error;
+  wire [31 : 0] coretest_read_data;
+  wire          coretest_error;
 
   // i2c connections
   wire          i2c_rxd_syn;
@@ -89,7 +89,6 @@ module coretest_trng(
   wire [7 : 0]  i2c_debug;
 
   // trng connections.
-  wire          trng_noise;
   reg           trng_cs;
   reg           trng_we;
   reg [7 : 0]   trng_address;
@@ -168,12 +167,12 @@ module coretest_trng(
 
                  .avalanche_noise(noise),
 
-                 .cs(trng_cs),
-                 .we(trng_we),
-                 .address(trng_address),
-                 .write_data(trng_write_data),
-                 .read_data(trng_read_data),
-                 .error(trng_error),
+                 .cs(coretest_cs),
+                 .we(coretest_we),
+                 .address(coretest_address),
+                 .write_data(coretest_write_data),
+                 .read_data(coretest_read_data),
+                 .error(coretest_error),
 
                  .debug(trng_debug),
                  .debug_update(trng_debug_update),
@@ -188,49 +187,55 @@ module coretest_trng(
   // Combinational data mux that handles addressing between
   // cores using the 32-bit memory like interface.
   //----------------------------------------------------------------
-  always @*
-    begin : address_mux
-      // Default assignments.
-      coretest_read_data   = 32'h00000000;
-      coretest_error       = 0;
-
-      i2c_cs               = 0;
-      i2c_we               = 0;
-      i2c_address          = 8'h00;
-      i2c_write_data       = 32'h00000000;
-
-      trng_cs              = 0;
-      trng_we              = 0;
-      trng_address         = 8'h00;
-      trng_write_data      = 32'h00000000;
-
-
-      case (coretest_address[15 : 12])
-        I2C_ADDR_PREFIX:
-          begin
-            i2c_cs             = coretest_cs;
-            i2c_we             = coretest_we;
-            i2c_address        = coretest_address[7 : 0];
-            i2c_write_data     = coretest_write_data;
-            coretest_read_data = i2c_read_data;
-            coretest_error     = i2c_error;
-          end
-
-        TRNG_ADDR_PREFIX:
-          begin
-            trng_cs            = coretest_cs;
-            trng_we            = coretest_we;
-            trng_address       = coretest_address[11 : 0];
-            trng_write_data    = coretest_write_data;
-            coretest_read_data = trng_read_data;
-            coretest_error     = trng_error;
-          end
-
-        default:
-          begin
-          end
-      endcase // case (coretest_address[15 : 8])
-    end // address_mux
+//  always @*
+//    begin : address_mux
+//      // Default assignments.
+//      coretest_read_data   = 32'h00000000;
+//      coretest_error       = 0;
+//
+//      i2c_cs               = 0;
+//      i2c_we               = 0;
+//      i2c_address          = 8'h00;
+//      i2c_write_data       = 32'h00000000;
+
+//      trng_cs              = 0;
+//      trng_we              = 0;
+//      trng_address         = 8'h00;
+//      trng_write_data      = 32'h00000000;
+
+//      trng_cs            = coretest_cs;
+//      trng_we            = coretest_we;
+//      trng_address       = coretest_address[11 : 0];
+//      trng_write_data    = coretest_write_data;
+//      coretest_read_data = trng_read_data;
+//      coretest_error     = trng_error;
+//
+//      case (coretest_address[13 : 12])
+//        I2C_ADDR_PREFIX:
+//          begin
+//            i2c_cs             = coretest_cs;
+//            i2c_we             = coretest_we;
+//            i2c_address        = coretest_address[7 : 0];
+//            i2c_write_data     = coretest_write_data;
+//            coretest_read_data = i2c_read_data;
+//            coretest_error     = i2c_error;
+//          end
+//
+//        TRNG_ADDR_PREFIX:
+//          begin
+//            trng_cs            = coretest_cs;
+//            trng_we            = coretest_we;
+//            trng_address       = coretest_address[11 : 0];
+//            trng_write_data    = coretest_write_data;
+//            coretest_read_data = trng_read_data;
+//            coretest_error     = trng_error;
+//          end
+//
+//        default:
+//          begin
+//          end
+//      endcase // case (coretest_address[15 : 12])
+//    end // address_mux
 
 endmodule // coretest_trng
 
diff --git a/src/rtl/novena_trng.v b/src/rtl/novena_trng.v
index 9d722b6..3630574 100644
--- a/src/rtl/novena_trng.v
+++ b/src/rtl/novena_trng.v
@@ -178,13 +178,16 @@ module novena_trng(
   wire       SDA_pd;
   wire       SDA_int;
   reg        clk25;
+  reg        reset_n;
 
   initial begin
-    clk25 <= 1'b0;
+    clk25   <= 1'b0;
+    reset_n <= 1'b0;
   end
 
   always @ (posedge clk) begin
     clk25 <= ~clk25;
+    reset_n <= 1'b1;
     EIM_A16 <= 1'b0;
     EIM_A17 <= 1'b0;
   end
@@ -200,8 +203,8 @@ module novena_trng(
 	               );
 
    coretest_trng coretest_trng_inst(
-		                    .clk(clk25),
-		                    .reset_n(1'b1),
+		                    .clk(clk),
+		                    .reset_n(reset_n),
 
                                     .noise(F_DX7),
                                     .debug(test_debug),