allow up to 4095 roms (was 255)

Author: nand2mario

src/nes_tang20k.v

@@ -432,7 +432,7 @@ reg [3:0] sd_state0 = 0;
 reg [19:0] timer;           // 37 times per second
 always @(posedge clk) timer <= timer + 1;
 
-//`define SD_REPORT
+// `define SD_REPORT
 
 always@(posedge clk)begin
     state_0<={2'b0, loader_done};
@@ -443,31 +443,35 @@ always@(posedge clk)begin
     case (timer)
     20'h00000: begin
       `print("sd: file_total=", STR);
+      sd_debug_reg = 2;
+    end
+    20'h10000: begin 
+      `print(sd_debug_out, 1);
       sd_debug_reg = 1;
     end
-    20'h10000: `print(sd_debug_out, 1);
-    20'h20000: begin
+    20'h20000: `print(sd_debug_out, 1);
+    20'h30000: begin
       `print(", file_start=", STR);
-      sd_debug_reg = 2;      
+      sd_debug_reg = 3;      
     end
-    20'h30000: `print(sd_debug_out, 1);
-    20'h40000: begin
+    20'h40000: `print(sd_debug_out, 1);
+    20'h50000: begin
       `print(", active=", STR);
-      sd_debug_reg = 3;      
+      sd_debug_reg = 4;      
     end
-    20'h50000: `print(sd_debug_out, 1);
-    20'h60000: begin
+    20'h60000: `print(sd_debug_out, 1);
+    20'h70000: begin
       `print(", total=", STR);
-      sd_debug_reg = 4;      
+      sd_debug_reg = 5;      
     end
-    20'h70000: `print(sd_debug_out, 1);
+    20'h80000: `print(sd_debug_out, 1);
     20'h80000: begin
       `print(", state=", STR);
-      sd_debug_reg = 5;      
+      sd_debug_reg = 6;      
     end
-    20'h90000: `print(sd_debug_out, 1);
-    20'ha0000: `print(", buttons=", STR);
-    20'hb0000: `print({nes_btn, nes_btn2}, 2);
+    20'ha0000: `print(sd_debug_out, 1);
+    20'hb0000: `print(", buttons=", STR);
+    20'hc0000: `print({nes_btn, nes_btn2}, 2);
     20'hf0000: `print("\n", STR);
     endcase
 `endif

src/sd_file_list_reader.v

@@ -30,7 +30,7 @@ module sd_file_list_reader #(
     input  wire       sddat0,            // FPGA only read SDDAT signal but never drive it
     // command interface
     input             op,                // 0: list root dir, 1: read file. rstn <= 0 to restart a new operation.
-    input       [9:0] read_file,         // file number to read for cmd=2
+    input      [11:0] read_file,         // file number to read for cmd=2
     output      [2:0] done,              // operation finished
     // status output (optional for user)
     output wire [3:0] card_stat,         // show the sdcard initialize status
@@ -40,7 +40,7 @@ module sd_file_list_reader #(
     // listing output (root directory, files only)
     output     [7:0]  list_name[0:51],   // name of current file, max 52 chars, [255:248] is first char, etc.
     output     [7:0]  list_namelen,
-    output reg [9:0]  list_file_num,     // number of current file: 0, 1...
+    output reg [11:0] list_file_num,     // number of current file: 0, 1...
     output            list_en,           // pulse on new list result
     // reading content data output (sync with clk)
     output reg        outen,             // when outen=1, a byte of file content is read out from outbyte

src/sd_loader.v

@@ -34,9 +34,9 @@ module SDLoader #(
 `include "font.vh"
 
 localparam [5:0] COLOR_BACK=13, COLOR_CURSOR=55, COLOR_TEXT=56;
-reg [4:0] active;       // within the page
-reg [9:0] file_total;   // max 1023 files
-reg [9:0] file_start = 1;   // file number is 1-based
+reg [4:0] active;           // within the page
+reg [11:0] file_total;      // max 4095 files
+reg [11:0] file_start = 1;  // file number is 1-based
 wire [4:0] total = file_total < file_start ? 0 :        // number of files in this page
                    file_total >= file_start + 19 ? 20 : file_total - file_start + 1;
 reg [4:0] cursor_now;   // current cursor under refresh
@@ -72,10 +72,10 @@ reg sd_loading;
 reg sd_op = 0;
 wire sd_done;
 reg sd_restart = 0;
-reg [9:0] sd_file;
+reg [11:0] sd_file;
 wire [7:0] sd_list_name[0:51];
 wire [7:0] sd_list_namelen;
-wire [9:0] sd_list_file;
+wire [11:0] sd_list_file;
 wire sd_list_en;
 
 // whether current sd_outbyte is valid NES data
@@ -135,7 +135,7 @@ always @(posedge clk) begin
                 // fill in actual pixels, one pixel per clock cycle
                 // so one file name takes 30*64=1920 cycles
                 overlay <= 1;
-                if (fn + file_start == sd_list_file[7:0] /* && ch < sd_list_namelen*/) begin
+                if (fn + file_start == sd_list_file) begin
                     if (FONT[sd_list_name[ch]][ny[2:0]][nx[2:0]])
                         color <= COLOR_TEXT;    // yellow
                     else
@@ -225,11 +225,12 @@ end
 
 always @* begin
     case (debug_reg)
-    8'h1: debug_out = file_total;
-    8'h2: debug_out = file_start;
-    8'h3: debug_out = active;
-    8'h4: debug_out = total;
-    8'h5: debug_out = state;
+    8'h1: debug_out = file_total[7:0];
+    8'h2: debug_out = file_total[11:8];
+    8'h3: debug_out = file_start;
+    8'h4: debug_out = active;
+    8'h5: debug_out = total;
+    8'h6: debug_out = state;
     default: debug_out = 0;
     endcase
 end