From 18aab51325f398891c74c384261bb0e7738c9078 Mon Sep 17 00:00:00 2001
From: Waylon Cude <waylon.cude@finzdani.net>
Date: Mon, 19 May 2025 16:13:35 -0700
Subject: [PATCH] Add debouncer TB and fixup on debouncer

---
 SDVD.xpr                     | 14 ++-------
 design/debouncer.sv          |  4 +++
 verification/debouncer_tb.sv | 55 ++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 11 deletions(-)

diff --git a/SDVD.xpr b/SDVD.xpr
index fc10aaa..b9cde0e 100644
--- a/SDVD.xpr
+++ b/SDVD.xpr
@@ -45,7 +45,7 @@
     <Option Name="SimulatorGccVersionActiveHdl" Val="9.3.0"/>
     <Option Name="BoardPart" Val="digilentinc.com:nexys-a7-100t:part0:1.2"/>
     <Option Name="BoardPartRepoPaths" Val="$PPRDIR/../../../.Xilinx/Vivado/2024.2/xhub/board_store/xilinx_board_store"/>
-    <Option Name="ActiveSimSet" Val="seconds_display_tb"/>
+    <Option Name="ActiveSimSet" Val="sim_1"/>
     <Option Name="DefaultLib" Val="xil_defaultlib"/>
     <Option Name="ProjectType" Val="Default"/>
     <Option Name="IPRepoPath" Val="$PPRDIR/../../../fpga/vivado-library"/>
@@ -61,7 +61,7 @@
     <Option Name="IPStaticSourceDir" Val="$PIPUSERFILESDIR/ipstatic"/>
     <Option Name="EnableBDX" Val="FALSE"/>
     <Option Name="DSABoardId" Val="nexys-a7-100t"/>
-    <Option Name="WTXSimLaunchSim" Val="9"/>
+    <Option Name="WTXSimLaunchSim" Val="16"/>
     <Option Name="WTModelSimLaunchSim" Val="0"/>
     <Option Name="WTQuestaLaunchSim" Val="0"/>
     <Option Name="WTIesLaunchSim" Val="0"/>
@@ -168,16 +168,8 @@
     </FileSet>
     <FileSet Name="sim_1" Type="SimulationSrcs" RelSrcDir="$PSRCDIR/sim_1" RelGenDir="$PGENDIR/sim_1">
       <Filter Type="Srcs"/>
-      <File Path="$PPRDIR/verification/segment_display/seconds_display_tb.sv">
-        <FileInfo>
-          <Attr Name="UsedIn" Val="synthesis"/>
-          <Attr Name="UsedIn" Val="implementation"/>
-          <Attr Name="UsedIn" Val="simulation"/>
-        </FileInfo>
-      </File>
       <File Path="$PPRDIR/verification/debouncer_tb.sv">
         <FileInfo>
-          <Attr Name="AutoDisabled" Val="1"/>
           <Attr Name="UsedIn" Val="synthesis"/>
           <Attr Name="UsedIn" Val="implementation"/>
           <Attr Name="UsedIn" Val="simulation"/>
@@ -185,7 +177,7 @@
       </File>
       <Config>
         <Option Name="DesignMode" Val="RTL"/>
-        <Option Name="TopModule" Val="seconds_display_tb"/>
+        <Option Name="TopModule" Val="debouncer_tb"/>
         <Option Name="TopLib" Val="xil_defaultlib"/>
         <Option Name="TransportPathDelay" Val="0"/>
         <Option Name="TransportIntDelay" Val="0"/>
diff --git a/design/debouncer.sv b/design/debouncer.sv
index 836d5f9..88a2c95 100644
--- a/design/debouncer.sv
+++ b/design/debouncer.sv
@@ -11,6 +11,10 @@ always_ff @(posedge clk) begin
         pressed <= 1;
     else if (pressed && !source)
         pressed <= 0;
+    else if (pressed && source)
+        pressed <= 0;
+    else if (!pressed && !source)
+        pressed <= 0;
 end
 
 
diff --git a/verification/debouncer_tb.sv b/verification/debouncer_tb.sv
index f98a0fa..a541ac4 100644
--- a/verification/debouncer_tb.sv
+++ b/verification/debouncer_tb.sv
@@ -1,8 +1,63 @@
+`timescale 1ns / 1ps
 module debouncer_tb;
 
 logic clk,reset,source;
 wire out;
 
+int errors;
+
 debouncer Dut (.*);
 
+initial begin
+    clk = 0;
+    forever #10 clk = ~clk;
+end
+
+initial begin
+    $display("Testing debouncer");
+    reset = 1;
+    source = 0;
+    @(posedge clk);
+    @(posedge clk);
+    reset = 0;
+    @(posedge clk);
+    source = 1;
+    #1;
+    assert (out == 1) else begin
+        $error("Output not brought high during first press");
+        errors++;
+    end
+    @(posedge clk);
+    #1;
+    assert (out == 0) else begin
+        $error("Output not brought low after first press");
+        errors++;
+    end
+    @(posedge clk);
+    source = 0;
+    @(posedge clk);
+    source = 1;
+    #1;
+    assert (out == 1) else begin
+        $error("Output not brought high during second press");
+        errors++;
+    end
+    source = 0;
+    @(posedge clk);
+    #1;
+    assert (out == 0) else begin
+        $error("Output not brought low after second press");
+        errors++;
+    end
+
+    if (errors == 0)
+        $display("Found no errors while testing debouncer");
+
+    $finish;
+
+end
+
+
+
+
 endmodule