RoCoN: USB CDC ACM use maximal packet length - 64 bytes.

[fpga/lx-cpu1/lx-rocon.git] / hw / dff2.vhd

diff --git a/hw/dff2.vhd b/hw/dff2.vhd
index eb48fc85366f73388091fb3fd97145d79fdbc0dc..a3d3c07a9d12caeb08ac261b5a129f3852161cd3 100644 (file)
--- a/hw/dff2.vhd
+++ b/hw/dff2.vhd
@@ -11,7 +11,6 @@ entity dff2 is
   port
        (
     clk_i   : in std_logic;
-               reset_i : in std_logic;
     d_i     : in std_logic;
     q_o     : out std_logic
   );
@@ -21,6 +20,12 @@ architecture behavioral of dff2 is
        signal d_2r   : std_logic;
        signal d_r    : std_logic;
   signal data_s : std_logic;
+
+       -- XST attributes
+  attribute REGISTER_DUPLICATION : string;
+       attribute REGISTER_DUPLICATION of d_2r : signal is "NO";
+       attribute REGISTER_DUPLICATION of d_r  : signal is "NO";
+
 begin
   q_o <= data_s;
 
@@ -28,10 +33,7 @@ seq:
        process
        begin
     wait until clk_i'event and clk_i = '1';
-               if reset_i = '1' then
-                       d_r    <= '0';
-                       data_s <= '0';
-               elsif d_2r = d_r then
+               if d_2r = d_r then
                        data_s <= d_r;
                end if;