From da7d026d0679d1f3dcaa134256194fa1afdd5f8c Mon Sep 17 00:00:00 2001
From: Waylon Cude <waylon.cude@finzdani.net>
Date: Sat, 17 May 2025 12:40:20 -0700
Subject: [PATCH 1/2] Add testbench for the seconds display

NOTE: This doesn't actually compile yet, but it should once changes to
the seconds display are pushed
---
 verification/seconds_display_tb.sv | 51 ++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 verification/seconds_display_tb.sv

diff --git a/verification/seconds_display_tb.sv b/verification/seconds_display_tb.sv
new file mode 100644
index 0000000..1a5e687
--- /dev/null
+++ b/verification/seconds_display_tb.sv
@@ -0,0 +1,51 @@
+module seconds_display_tb;
+int errors = 0;
+logic [5:0] seconds;
+wire [6:0] display_tens;
+wire [6:0] display_ones;
+
+logic [6:0] expected_tens;
+logic [6:0] expected_ones;
+
+seconds_display Dut(.*);
+initial begin
+    $display("Testing seconds_display");
+    for (seconds=0; seconds<60; seconds++) begin
+        expected_ones = encode_number(seconds % 10);
+        expected_tens = encode_number(seconds /10);
+        #1
+        if (display_ones !== expected_ones) begin
+            errors++;
+            $display("Failed ones test case, displayed = %b, expected = %b",
+                     display_ones,
+                     expected_ones);
+        end
+        else
+        if (display_tens !== expected_tens) begin
+            errors++;
+            $display("Failed tens test case, displayed = %b, expected = %b",
+                     display_tens,
+                     expected_tens);
+        end
+    end
+
+    if (errors == 0)
+        $display("All tests passing");
+end
+
+endmodule
+
+function automatic logic [6:0] encode_number(logic [5:0] num);
+    case (num)
+        0: return 7'b1111110;
+        1: return 7'b0000110;
+        2: return 7'b1101101;
+        3: return 7'b1111001;
+        4: return 7'b0110011;
+        5: return 7'b1011011;
+        6: return 7'b1011111;
+        7: return 7'b1110000;
+        8: return 7'b1111111;
+        9: return 7'b1111011;
+    endcase
+endfunction

From 2fde75a3309fefbda31473e8fcad787735b5ace7 Mon Sep 17 00:00:00 2001
From: Waylon Cude <waylon.cude@finzdani.net>
Date: Mon, 19 May 2025 15:21:53 -0700
Subject: [PATCH 2/2] Added a in-progress top file

Some of this stuff should get split out into 7-segment logic probably,
having logic in the top file seems like a bad call
---
 Nexys-A7-100T-Master.xdc       | 40 ++++++++++----------
 SDVD.xpr                       | 20 ++++++++--
 design/display_anode_driver.sv | 11 ++++++
 design/low_freq_clock_gen.sv   | 45 +++++++++++++++++++++++
 design/nexys_a7_top.sv         | 67 ++++++++++++++++++++++++++++++++++
 design/playback_controller.sv  |  7 +++-
 design/sdvd_defs.sv            |  7 ++++
 7 files changed, 172 insertions(+), 25 deletions(-)
 create mode 100644 design/display_anode_driver.sv
 create mode 100644 design/low_freq_clock_gen.sv
 create mode 100644 design/nexys_a7_top.sv
 create mode 100644 design/sdvd_defs.sv

diff --git a/Nexys-A7-100T-Master.xdc b/Nexys-A7-100T-Master.xdc
index afd0916..5003bed 100644
--- a/Nexys-A7-100T-Master.xdc
+++ b/Nexys-A7-100T-Master.xdc
@@ -5,8 +5,8 @@
 ## Note: As the Nexys 4 DDR was rebranded to the Nexys A7 with no substantial changes, this XDC file will also work for the Nexys 4 DDR.
 
 ## Clock signal
-#set_property -dict { PACKAGE_PIN E3    IOSTANDARD LVCMOS33 } [get_ports { CLK100MHZ }]; #IO_L12P_T1_MRCC_35 Sch=clk100mhz
-#create_clock -add -name sys_clk_pin -period 10.00 -waveform {0 5} [get_ports {CLK100MHZ}];
+set_property -dict { PACKAGE_PIN E3    IOSTANDARD LVCMOS33 } [get_ports { CLK100MHZ }]; #IO_L12P_T1_MRCC_35 Sch=clk100mhz
+create_clock -add -name sys_clk_pin -period 10.00 -waveform {0 5} [get_ports {CLK100MHZ}];
 
 
 ##Switches
@@ -54,31 +54,31 @@
 #set_property -dict { PACKAGE_PIN N16   IOSTANDARD LVCMOS33 } [get_ports { LED17_R }]; #IO_L11N_T1_SRCC_14 Sch=led17_r
 
 ##7 segment display
-#set_property -dict { PACKAGE_PIN T10   IOSTANDARD LVCMOS33 } [get_ports { CA }]; #IO_L24N_T3_A00_D16_14 Sch=ca
-#set_property -dict { PACKAGE_PIN R10   IOSTANDARD LVCMOS33 } [get_ports { CB }]; #IO_25_14 Sch=cb
-#set_property -dict { PACKAGE_PIN K16   IOSTANDARD LVCMOS33 } [get_ports { CC }]; #IO_25_15 Sch=cc
-#set_property -dict { PACKAGE_PIN K13   IOSTANDARD LVCMOS33 } [get_ports { CD }]; #IO_L17P_T2_A26_15 Sch=cd
-#set_property -dict { PACKAGE_PIN P15   IOSTANDARD LVCMOS33 } [get_ports { CE }]; #IO_L13P_T2_MRCC_14 Sch=ce
-#set_property -dict { PACKAGE_PIN T11   IOSTANDARD LVCMOS33 } [get_ports { CF }]; #IO_L19P_T3_A10_D26_14 Sch=cf
-#set_property -dict { PACKAGE_PIN L18   IOSTANDARD LVCMOS33 } [get_ports { CG }]; #IO_L4P_T0_D04_14 Sch=cg
+set_property -dict { PACKAGE_PIN T10   IOSTANDARD LVCMOS33 } [get_ports { CA }]; #IO_L24N_T3_A00_D16_14 Sch=ca
+set_property -dict { PACKAGE_PIN R10   IOSTANDARD LVCMOS33 } [get_ports { CB }]; #IO_25_14 Sch=cb
+set_property -dict { PACKAGE_PIN K16   IOSTANDARD LVCMOS33 } [get_ports { CC }]; #IO_25_15 Sch=cc
+set_property -dict { PACKAGE_PIN K13   IOSTANDARD LVCMOS33 } [get_ports { CD }]; #IO_L17P_T2_A26_15 Sch=cd
+set_property -dict { PACKAGE_PIN P15   IOSTANDARD LVCMOS33 } [get_ports { CE }]; #IO_L13P_T2_MRCC_14 Sch=ce
+set_property -dict { PACKAGE_PIN T11   IOSTANDARD LVCMOS33 } [get_ports { CF }]; #IO_L19P_T3_A10_D26_14 Sch=cf
+set_property -dict { PACKAGE_PIN L18   IOSTANDARD LVCMOS33 } [get_ports { CG }]; #IO_L4P_T0_D04_14 Sch=cg
 #set_property -dict { PACKAGE_PIN H15   IOSTANDARD LVCMOS33 } [get_ports { DP }]; #IO_L19N_T3_A21_VREF_15 Sch=dp
-#set_property -dict { PACKAGE_PIN J17   IOSTANDARD LVCMOS33 } [get_ports { AN[0] }]; #IO_L23P_T3_FOE_B_15 Sch=an[0]
-#set_property -dict { PACKAGE_PIN J18   IOSTANDARD LVCMOS33 } [get_ports { AN[1] }]; #IO_L23N_T3_FWE_B_15 Sch=an[1]
-#set_property -dict { PACKAGE_PIN T9    IOSTANDARD LVCMOS33 } [get_ports { AN[2] }]; #IO_L24P_T3_A01_D17_14 Sch=an[2]
-#set_property -dict { PACKAGE_PIN J14   IOSTANDARD LVCMOS33 } [get_ports { AN[3] }]; #IO_L19P_T3_A22_15 Sch=an[3]
-#set_property -dict { PACKAGE_PIN P14   IOSTANDARD LVCMOS33 } [get_ports { AN[4] }]; #IO_L8N_T1_D12_14 Sch=an[4]
-#set_property -dict { PACKAGE_PIN T14   IOSTANDARD LVCMOS33 } [get_ports { AN[5] }]; #IO_L14P_T2_SRCC_14 Sch=an[5]
-#set_property -dict { PACKAGE_PIN K2    IOSTANDARD LVCMOS33 } [get_ports { AN[6] }]; #IO_L23P_T3_35 Sch=an[6]
-#set_property -dict { PACKAGE_PIN U13   IOSTANDARD LVCMOS33 } [get_ports { AN[7] }]; #IO_L23N_T3_A02_D18_14 Sch=an[7]
+set_property -dict { PACKAGE_PIN J17   IOSTANDARD LVCMOS33 } [get_ports { AN[0] }]; #IO_L23P_T3_FOE_B_15 Sch=an[0]
+set_property -dict { PACKAGE_PIN J18   IOSTANDARD LVCMOS33 } [get_ports { AN[1] }]; #IO_L23N_T3_FWE_B_15 Sch=an[1]
+set_property -dict { PACKAGE_PIN T9    IOSTANDARD LVCMOS33 } [get_ports { AN[2] }]; #IO_L24P_T3_A01_D17_14 Sch=an[2]
+set_property -dict { PACKAGE_PIN J14   IOSTANDARD LVCMOS33 } [get_ports { AN[3] }]; #IO_L19P_T3_A22_15 Sch=an[3]
+set_property -dict { PACKAGE_PIN P14   IOSTANDARD LVCMOS33 } [get_ports { AN[4] }]; #IO_L8N_T1_D12_14 Sch=an[4]
+set_property -dict { PACKAGE_PIN T14   IOSTANDARD LVCMOS33 } [get_ports { AN[5] }]; #IO_L14P_T2_SRCC_14 Sch=an[5]
+set_property -dict { PACKAGE_PIN K2    IOSTANDARD LVCMOS33 } [get_ports { AN[6] }]; #IO_L23P_T3_35 Sch=an[6]
+set_property -dict { PACKAGE_PIN U13   IOSTANDARD LVCMOS33 } [get_ports { AN[7] }]; #IO_L23N_T3_A02_D18_14 Sch=an[7]
 
 ##CPU Reset Button
-#set_property -dict { PACKAGE_PIN C12   IOSTANDARD LVCMOS33 } [get_ports { CPU_RESETN }]; #IO_L3P_T0_DQS_AD1P_15 Sch=cpu_resetn
+set_property -dict { PACKAGE_PIN C12   IOSTANDARD LVCMOS33 } [get_ports { CPU_RESETN }]; #IO_L3P_T0_DQS_AD1P_15 Sch=cpu_resetn
 
 ##Buttons
-#set_property -dict { PACKAGE_PIN N17   IOSTANDARD LVCMOS33 } [get_ports { BTNC }]; #IO_L9P_T1_DQS_14 Sch=btnc
+set_property -dict { PACKAGE_PIN N17   IOSTANDARD LVCMOS33 } [get_ports { BTNC }]; #IO_L9P_T1_DQS_14 Sch=btnc
 #set_property -dict { PACKAGE_PIN M18   IOSTANDARD LVCMOS33 } [get_ports { BTNU }]; #IO_L4N_T0_D05_14 Sch=btnu
 #set_property -dict { PACKAGE_PIN P17   IOSTANDARD LVCMOS33 } [get_ports { BTNL }]; #IO_L12P_T1_MRCC_14 Sch=btnl
-#set_property -dict { PACKAGE_PIN M17   IOSTANDARD LVCMOS33 } [get_ports { BTNR }]; #IO_L10N_T1_D15_14 Sch=btnr
+set_property -dict { PACKAGE_PIN M17   IOSTANDARD LVCMOS33 } [get_ports { BTNR }]; #IO_L10N_T1_D15_14 Sch=btnr
 #set_property -dict { PACKAGE_PIN P18   IOSTANDARD LVCMOS33 } [get_ports { BTND }]; #IO_L9N_T1_DQS_D13_14 Sch=btnd
 
 
diff --git a/SDVD.xpr b/SDVD.xpr
index 0573c12..b371300 100644
--- a/SDVD.xpr
+++ b/SDVD.xpr
@@ -48,6 +48,7 @@
     <Option Name="ActiveSimSet" Val="sim_1"/>
     <Option Name="DefaultLib" Val="xil_defaultlib"/>
     <Option Name="ProjectType" Val="Default"/>
+    <Option Name="IPRepoPath" Val="$PPRDIR/../../../fpga/vivado-library"/>
     <Option Name="IPOutputRepo" Val="$PCACHEDIR/ip"/>
     <Option Name="IPDefaultOutputPath" Val="$PGENDIR/sources_1"/>
     <Option Name="IPCachePermission" Val="read"/>
@@ -98,6 +99,13 @@
           <Attr Name="UsedIn" Val="simulation"/>
         </FileInfo>
       </File>
+      <File Path="$PPRDIR/design/display_anode_driver.sv">
+        <FileInfo>
+          <Attr Name="UsedIn" Val="synthesis"/>
+          <Attr Name="UsedIn" Val="implementation"/>
+          <Attr Name="UsedIn" Val="simulation"/>
+        </FileInfo>
+      </File>
       <File Path="$PPRDIR/design/playback_controller.sv">
         <FileInfo>
           <Attr Name="UsedIn" Val="synthesis"/>
@@ -107,7 +115,13 @@
       </File>
       <File Path="$PPRDIR/design/seconds_display.sv">
         <FileInfo>
-          <Attr Name="AutoDisabled" Val="1"/>
+          <Attr Name="UsedIn" Val="synthesis"/>
+          <Attr Name="UsedIn" Val="implementation"/>
+          <Attr Name="UsedIn" Val="simulation"/>
+        </FileInfo>
+      </File>
+      <File Path="$PPRDIR/design/nexys_a7_top.sv">
+        <FileInfo>
           <Attr Name="UsedIn" Val="synthesis"/>
           <Attr Name="UsedIn" Val="implementation"/>
           <Attr Name="UsedIn" Val="simulation"/>
@@ -115,7 +129,7 @@
       </File>
       <Config>
         <Option Name="DesignMode" Val="RTL"/>
-        <Option Name="TopModule" Val="Playback_Controller"/>
+        <Option Name="TopModule" Val="nexys_a7_top"/>
         <Option Name="TopAutoSet" Val="TRUE"/>
       </Config>
     </FileSet>
@@ -143,7 +157,7 @@
       </File>
       <Config>
         <Option Name="DesignMode" Val="RTL"/>
-        <Option Name="TopModule" Val="Playback_Controller"/>
+        <Option Name="TopModule" Val="nexys_a7_top"/>
         <Option Name="TopLib" Val="xil_defaultlib"/>
         <Option Name="TopAutoSet" Val="TRUE"/>
         <Option Name="TransportPathDelay" Val="0"/>
diff --git a/design/display_anode_driver.sv b/design/display_anode_driver.sv
new file mode 100644
index 0000000..cb9d790
--- /dev/null
+++ b/design/display_anode_driver.sv
@@ -0,0 +1,11 @@
+// NOTE: This expects to be driven with a 100khz clock
+module display_anode_driver(input logic clk, input logic reset, output logic [7:0] AN);
+
+// This is just a shift register that drives each anode individually
+always_ff @(posedge clk) begin
+    if (reset)
+        AN <= 1;
+    else
+        AN <= {AN[6:0], AN[7]};
+end
+endmodule
diff --git a/design/low_freq_clock_gen.sv b/design/low_freq_clock_gen.sv
new file mode 100644
index 0000000..60b68bc
--- /dev/null
+++ b/design/low_freq_clock_gen.sv
@@ -0,0 +1,45 @@
+`include "sdvd_defs.sv"
+import sdvd_defs::SPEED;
+// Takes in a 100MHz clock and generates the very low freq signals needed
+// for driving the control logic
+module low_freq_clock_gen(
+    input logic clk, reset,
+    input SPEED speed,
+    output logic clk1k, clk10h, seconds_pulse
+);
+
+logic [$clog2(100_000_000):0] counter;
+logic [$clog2(4000):0] seconds_counter;
+logic clk4k;
+
+assign clk1k = (counter % (100_000_000/1000)) != 0;
+assign clk10h = (counter % (100_000_000/10)) != 0;
+assign clk4k = (counter % (100_000_000/4000)) != 0;
+
+always_ff @(posedge clk) begin
+    // NOTE: This generates a pulse on the same clock cycle that reset is
+    // asserted. Is that bad??
+    if (reset)
+        counter <= 0;
+    // Roll the counter over back to zero every second
+    else if (counter == 99_999_999)
+        counter <= 0;
+    else
+        counter <= counter + 1;
+
+    // This logic handles the variable-speed seconds counter
+    if (reset) begin
+        seconds_pulse <= 0;
+        seconds_counter <= 0;
+    end
+    else if (clk4k && seconds_counter >= 4000) begin
+        seconds_counter <= seconds_counter-4000;
+        seconds_pulse <= 1;
+    end
+    else if (clk4k) begin
+        seconds_pulse <= 0;
+        seconds_counter <= seconds_counter + {9'b0, speed};
+    end
+end
+
+endmodule
diff --git a/design/nexys_a7_top.sv b/design/nexys_a7_top.sv
new file mode 100644
index 0000000..b1e70c1
--- /dev/null
+++ b/design/nexys_a7_top.sv
@@ -0,0 +1,67 @@
+`include "sdvd_defs.sv"
+import sdvd_defs::SPEED;
+module nexys_a7_top(
+    input logic CLK100MHZ, CPU_RESETN,
+    input logic BTNC, BTNR,
+    output logic [7:0] CA,CB,CC,CD,CE,CF,CG,
+    output logic [7:0] AN
+);
+
+// Active high reset
+wire reset;
+assign reset = ~CPU_RESETN;
+
+logic clk_1khz, clk_10hz;
+logic seconds_pulse;
+
+SPEED speed;
+
+// Map C{A-G} to an array of 7-segment displays
+wire [6:0] segments [7:0];
+for (genvar i = 0; i<8; i++) begin: segmentGenerate
+    assign {CG[i],CF[i],CE[i],CD[i],CC[i],CB[i],CA[i]} = segments[i];
+end
+
+logic [$clog2(60):0] seconds;
+logic [$clog2(60):0] minutes;
+logic [$clog2(60):0] hours;
+
+low_freq_clock_gen clockGen(CLK100MHZ, reset, speed, clk_1khz, clk_10hz, seconds_pulse);
+
+// Count the number on seconds, hours, and minutes elapsed
+// If the speed is faster this will pulse more often than once a second
+// but will still theoretically be a second of video time
+always_ff @(posedge seconds_pulse) begin
+    if (reset) begin
+        seconds <= 0;
+        minutes <= 0;
+        hours <= 0;
+    end
+    else if (seconds == 59) begin
+        seconds <= 0;
+        if (minutes == 59) begin
+            minutes <= 0;
+            hours <= hours + 1;
+        end
+        else
+            minutes <= minutes + 1;
+    end
+    else
+        seconds <= seconds + 1;
+end
+
+display_anode_driver anodeDriver(clk_1khz,reset,AN);
+
+seconds_display secondsSegment (seconds, segments[1], segments[0]);
+seconds_display minutesSegment (minutes, segments[3], segments[2]);
+seconds_display hoursSegment (hours, segments[5], segments[4]);
+
+// Run the playback speed state machine at a lower rate
+// Gets rid of button bouncing
+playback_controller playbackController (clk_10hz,reset,BTNC, BTNR, speed);
+
+
+
+
+
+endmodule
diff --git a/design/playback_controller.sv b/design/playback_controller.sv
index cda3c60..05a49fe 100644
--- a/design/playback_controller.sv
+++ b/design/playback_controller.sv
@@ -1,4 +1,7 @@
-module Playback_Controller(
+`include "sdvd_defs.sv"
+import sdvd_defs::SPEED;
+
+module playback_controller(
     // This clock should be reasonably slow
     input logic clk,
     input logic reset,
@@ -8,7 +11,7 @@ module Playback_Controller(
     input logic ff,
 
     // Output is 0, 1x, 2x, 4x, or 8x
-    output wire [3:0] speed
+    output SPEED speed
 );
 
 wire play_pulse,ff_pulse;
diff --git a/design/sdvd_defs.sv b/design/sdvd_defs.sv
new file mode 100644
index 0000000..b1c20e3
--- /dev/null
+++ b/design/sdvd_defs.sv
@@ -0,0 +1,7 @@
+`ifndef SDVD_DEFS
+`define SDVD_DEFS
+package sdvd_defs;
+    // Playback speed type
+    typedef logic [3:0] SPEED;
+endpackage
+`endif