(1) Added a state in the write fifo machine to actually drop request between csprng data words. (2) Updated the testbench with better test vector generation.

1 files changed, 12 insertions, 5 deletions

diff --git a/src/rtl/trng_csprng_fifo.v b/src/rtl/trng_csprng_fifo.v
index e4abc26..9c52ef5 100644
--- a/src/rtl/trng_csprng_fifo.v
+++ b/src/rtl/trng_csprng_fifo.v
@@ -60,8 +60,7 @@ module trng_csprng_fifo(
   localparam FIFO_MAX       = (2 ** FIFO_ADDR_BITS) - 1;
 
   localparam WR_IDLE    = 0;
-  localparam WR_WAIT    = 1;
-  localparam WR_WRITE   = 2;
+  localparam WR_STORE   = 1;
   localparam WR_DISCARD = 7;
 
   localparam RD_IDLE    = 0;
@@ -453,13 +452,21 @@ module trng_csprng_fifo(
 
                 if (csprng_data_valid)
                   begin
-                    fifo_mem_we      = 1;
-                    wr_ptr_inc       = 1;
-                    fifo_ctr_inc     = 1;
+                    wr_ctrl_new = WR_STORE;
+                    wr_ctrl_we  = 1;
                   end
               end
           end
 
+        WR_STORE:
+          begin
+            fifo_mem_we  = 1;
+            wr_ptr_inc   = 1;
+            fifo_ctr_inc = 1;
+            wr_ctrl_new  = WR_IDLE;
+            wr_ctrl_we   = 1;
+          end
+
         WR_DISCARD:
           begin
             fifo_ctr_rst     = 1;