move stuff around

1 files changed, 53 insertions, 0 deletions

diff --git a/playground/tst_delay_tb.v b/playground/tst_delay_tb.v
new file mode 100644
index 0000000..5812068
--- /dev/null
+++ b/playground/tst_delay_tb.v
@@ -0,0 +1,53 @@
+// try to figure out how iverilog samples edges
+`timescale 1us/1us
+
+module tst_delay_tb;
+
+reg clk_i;
+reg data_i;
+wire data_o;
+
+tst_delay uut (
+  .clk_i(clk_i),
+  .data_i(data_i),
+  .data_o(data_o)
+);
+
+string filename;
+initial begin
+`ifdef DUMP_FILE_NAME
+  filename=`DUMP_FILE_NAME;
+`else
+  filename="tst_delay.lxt2";
+`endif
+  $dumpfile(filename); $dumpvars();
+  clk_i = 0;
+  data_i = 0;
+end
+
+always #10 clk_i = ~clk_i;
+
+initial begin
+  #9
+  data_i = 1;
+  #2
+  data_i = 0;
+
+  /* verilator lint_off INITIALDLY */
+  // note the <= assignment
+  #19
+  data_i <= 1;
+  /* verilator lint_on INITIALDLY */
+
+  #1
+  data_i = 0;
+  // note the = assignment
+  #19
+  data_i = 1;
+  #1
+  data_i = 0;
+  #40
+  $finish();
+end
+
+endmodule