From a473a6ff9cd021018426ce0f0024fc99386e85ff Mon Sep 17 00:00:00 2001
From: Aadi Desai <21363892+supleed2@users.noreply.github.com>
Date: Sat, 11 Mar 2023 18:04:53 +0000
Subject: [PATCH] Add Sawtooth Generator Block

---
 rtl/genSaw.sv | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 rtl/genSaw.sv

diff --git a/rtl/genSaw.sv b/rtl/genSaw.sv
new file mode 100644
index 0000000..05030a5
--- /dev/null
+++ b/rtl/genSaw.sv
@@ -0,0 +1,39 @@
+`default_nettype none
+
+module genSaw
+( input  var        i_clk48
+, input  var        i_rst48_n
+, input  var        i_pause
+, input  var [23:0] i_tf
+, output var [47:0] o_lr
+, output var        o_new_pulse
+);
+
+logic [8:0] clk_div;
+always_ff @(posedge i_clk48)
+  if (!i_rst48_n)             clk_div <= 0;
+  else if (clk_div == 9'd500) clk_div <= 0;
+  else                        clk_div <= clk_div + 1;
+
+logic clk_48k;
+always_ff @(posedge i_clk48)
+  if (!i_rst48_n)             clk_48k <= 0;
+  else if (clk_div == 9'd500) clk_48k <= ~clk_48k;
+
+logic clk_48k_past;
+always_ff @(posedge i_clk48)
+  clk_48k_past <= clk_48k;
+
+assign o_new_pulse = clk_48k && !clk_48k_past;
+
+logic [23:0] saw_step;
+assign saw_step = (24'd699 * i_tf) >> 1;
+
+logic [23:0] waveform;
+always_ff @(posedge clk_48k)
+  if (!i_rst48_n)    waveform <= '0;
+  else if (!i_pause) waveform <= waveform + saw_step;
+
+assign o_lr = {waveform, waveform};
+
+endmodule