Its working! Demo commit

We have something at least, audio is working and sounding dang good

design/audio/pwm.sv

@@ -18,7 +18,7 @@ module pwm(
 );
 // This  can't be 16 or we are slowing the audio rate down by a factor of
 // 2^5=32
-parameter DEPTH=8;
+parameter DEPTH=11;
 
 logic [DEPTH-1:0] pulse_counter;
 logic [15:0] sample_buffer;

design/modular_clock_gen.sv

@@ -1,6 +1,6 @@
 module modular_clock_gen(
     input clk, reset,
-    output oclk
+    output logic oclk
 );
 parameter DIVISOR;
 
@@ -8,7 +8,8 @@ logic [$clog2(DIVISOR)-1:0] counter;
 
 // clock will be high for about half of the cycle, depending on integer
 // rounding
-assign oclk = counter < (DIVISOR/2);
+// OOPS this makes it combinational
+//assign oclk = counter < (DIVISOR/2);
 
 always_ff @(posedge clk) begin
     if (reset)
@@ -17,6 +18,8 @@ always_ff @(posedge clk) begin
         counter <= DIVISOR-1;
     else 
         counter <= counter - 1;
+
+    oclk <= counter < (DIVISOR/2);
 end
 
 endmodule

design/nexys_a7_top.sv

@@ -102,7 +102,7 @@ audio_buffer audioBuffer(
     audio_interface.receiver
 );
 
-rom_sd romSdPlayer(clk_1mhz,reset,sd_ready,audio_interface.driver);
+rom_sd #("even_flow_16.mem") romSdPlayer(clk_1mhz,reset,sd_ready,audio_interface.driver);
 
 
 endmodule

design/sd/rom_sd.sv

@@ -21,7 +21,7 @@ typedef enum logic [3:0]{
 state_t current, next;
 // First we write 2048B into the memory buffer, then signal to play it and
 // wait for half signal to avoid overwriting memory
-logic [16:0] rom_addr;
+logic [18:0] rom_addr;
 logic [7:0] rom_data;
 logic rom_enable;
 logic buffer_half;
@@ -33,7 +33,7 @@ logic buffer_half;
 // The ROM has 17 address bits and 8 data bits to store 128KiB, more than
 // enough for one second of 48khz audio
 xpm_memory_sprom #(
-  .ADDR_WIDTH_A(17),               // DECIMAL
+  .ADDR_WIDTH_A(19),               // DECIMAL
   .AUTO_SLEEP_TIME(0),             // DECIMAL
   .CASCADE_HEIGHT(0),              // DECIMAL
   .ECC_BIT_RANGE("7:0"),           // String
@@ -44,7 +44,7 @@ xpm_memory_sprom #(
   .MEMORY_INIT_PARAM(""),         // String
   .MEMORY_OPTIMIZATION("true"),    // String
   .MEMORY_PRIMITIVE("auto"),       // String
-  .MEMORY_SIZE(131072*8),          // DECIMAL
+  .MEMORY_SIZE((1<<19)*8),          // DECIMAL
   .MESSAGE_CONTROL(0),             // DECIMAL
   .RAM_DECOMP("auto"),             // String
   .READ_DATA_WIDTH_A(8),           // DECIMAL