Fixup to get main demo working

This adds some unnecessary stuff into the debug core  that I used to
troubleshoot. There are like 5 bugfixes here. Especially of note is the
low freq clock gen, I was trying to use modulo like you would do in a
computer program but it was too slow, so I had to move the logic around
a bunch.

design/segment_display/display_anode_driver.sv

@@ -1,11 +1,20 @@
 // 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);
+module display_anode_driver(
+    input logic clk, 
+    input logic reset, 
+    output logic [7:0] AN, 
+    output logic [2:0] mux_select);
 
 // This is just a shift register that drives each anode individually
 always_ff @(posedge clk) begin
-    if (reset)
-        AN <= 1;
-    else
+    if (reset) begin
+        AN <= '1 - 1;
+        mux_select <= 0;
+    end
+    else begin
         AN <= {AN[6:0], AN[7]};
+        // Letting this overflow will automatically reset it
+        mux_select <= mux_select + 1;
+    end
 end
 endmodule