2 files changed, 32 insertions, 3 deletions
diff --git a/debounce.tb.v b/debounce.tb.v
index 36f3a27..7501e2b 100644
--- a/debounce.tb.v
+++ b/debounce.tb.v
@@ -16,6 +16,7 @@ debounce uut(
   .signal_i(signal_i),
   .signal_o(signal_o)
 );
+defparam uut.STABLE_PERIOD = 5;
 
 initial begin
   $dumpfile("debounce.lxt2"); $dumpvars();
@@ -51,7 +52,7 @@ initial begin
   #500
   signal_i <= ~signal_i;
 
-  #105
+  #500
   $finish();
 end
 
diff --git a/debounce.v b/debounce.v
index efeb845..704a588 100644
--- a/debounce.v
+++ b/debounce.v
@@ -5,11 +5,39 @@ module debounce (
   output reg signal_o
 );
 
+parameter STABLE_PERIOD = 50;
+parameter INIT_SIG_STATE = 1'b1;
+
+reg [31:0] clk_counter;
+reg prev_state;
+
 always @(posedge clk_i or negedge rst_i) begin
   if (!rst_i) begin
-    
+    clk_counter <= 0;
+    prev_state <= INIT_SIG_STATE;
+    signal_o <= INIT_SIG_STATE;
+  end else begin
+    clk_counter <= clk_counter + 1;
+
+    if (signal_i != prev_state) begin
+      clk_counter <= 0;
+      prev_state <= signal_i;
+    end
+
+    if (clk_counter == STABLE_PERIOD) begin
+      signal_o <= signal_i;
+    end
   end
-  signal_o <= signal_i;
 end
 
+// Learning?
+// Apparently, (and obviously, when you think about it),
+// it's not possible to drive a signal by two blocks
+// always @(signal_i) begin
+//   if (signal_i != prev_state) begin
+//     clk_counter <= 0;
+//     prev_state <= signal_i;
+//   end
+// end
+
 endmodule