(1) Updated qr interface to include clock and reset needed for internal pipeline registers. (2) Added testbench for the qr module. (3) Added qr simulation target. (4) Added lint support.

1 files changed, 29 insertions, 0 deletions

diff --git a/src/rtl/chacha_qr.v b/src/rtl/chacha_qr.v
index 42e644c..e1ddbd8 100644
--- a/src/rtl/chacha_qr.v
+++ b/src/rtl/chacha_qr.v
@@ -40,6 +40,9 @@
 //======================================================================
 
 module chacha_qr(
+                 input wire           clk,
+                 input wire           reset_n,
+
                  input wire [31 : 0]  a,
                  input wire [31 : 0]  b,
                  input wire [31 : 0]  c,
@@ -52,6 +55,13 @@ module chacha_qr(
                 );
 
   //----------------------------------------------------------------
+  // Registers including update variables and write enable.
+  //----------------------------------------------------------------
+  reg [31 : 0] a0_reg;
+  reg [31 : 0] a0_new;
+
+
+  //----------------------------------------------------------------
   // Wires.
   //----------------------------------------------------------------
   reg [31 : 0] internal_a_prim;
@@ -70,6 +80,23 @@ module chacha_qr(
 
 
   //----------------------------------------------------------------
+  // reg_update
+  //----------------------------------------------------------------
+  always @ (posedge clk)
+    begin : reg_update
+      if (!reset_n)
+        begin
+          a0_reg <= 32'h0;
+        end
+
+      else
+        begin
+          a0_reg <= a0_new;
+        end
+    end // reg_update
+
+
+  //----------------------------------------------------------------
   // qr
   //
   // The actual quarterround function.
@@ -93,6 +120,8 @@ module chacha_qr(
       reg [31 : 0] d3;
 
       a0 = a + b;
+      a0_new = a + b;
+
       d0 = d ^ a0;
       d1 = {d0[15 : 0], d0[31 : 16]};
       c0 = c + d1;