led_toggle: Use edge timing, logic

1 files changed, 20 insertions, 20 deletions

diff --git a/led_toggle.tb.v b/led_toggle.tb.v
index 95bfe7d..a883af4 100644
--- a/led_toggle.tb.v
+++ b/led_toggle.tb.v
@@ -3,11 +3,11 @@
 module led_toggle_tb (
 );
 
-reg clk_i;
-reg rst_i;
-reg key_i;
-wire [5:0] led;
-integer i = 0;
+logic clk_i;
+logic rst_i;
+logic key_i;
+
+logic [5:0] led;
 
 led_toggle #(.STABLE_PERIOD(2)) uut(
   .rst_i(rst_i),
@@ -24,12 +24,12 @@ initial begin
   filename="led_toggle.lxt2";
 `endif
   $dumpfile(filename); $dumpvars();
-  clk_i <= 0;
-  key_i <= 1'b1;
+  clk_i = 0;
+  key_i = 1'b1;
   #1
-  rst_i <= 0;
+  rst_i = 0;
   #1
-  rst_i <= 1;
+  rst_i = 1;
 end
 
 always #10 clk_i = ~clk_i;
@@ -37,23 +37,23 @@ always #10 clk_i = ~clk_i;
 
 initial begin
   // initial key press
-  #25
-  key_i <= ~key_i;
-  #40
-  key_i <= ~key_i;
+  #13
+  key_i = ~key_i;
+  repeat(2) @(negedge clk_i);
+  key_i = ~key_i;
 
   // try bouncing
 
-  #50
+  repeat(3) @(negedge clk_i);
 
-  for (i=0; i < 19; i = i + 1) begin
-    #20
-    key_i <= ~key_i;
+  for (integer i=0; i < 19; i = i + 1) begin
+    @(negedge clk_i);
+    key_i = ~key_i;
   end
-  #200
-  key_i <= ~key_i;
+  repeat(10) @(negedge clk_i);
+  key_i = ~key_i;
 
-  #205
+  repeat(10) @(negedge clk_i);
   $finish();
 end