IP

[fpgaboy.git] / LCDC.v

diff --git a/LCDC.v b/LCDC.v
index cb204d5df1e5c6b58b0761cd4474c099f6abf946..c550288a04df9375c35a3b9d1e03e084238e15f1 100644 (file)
--- a/LCDC.v
+++ b/LCDC.v
@@ -135,8 +135,8 @@ module LCDC(
         * Tile data from 8000-8FFF or 8800-97FF
         * Background tile maps 9800-9BFF or 9C00-9FFF
         */
-       reg [7:0] tiledatahigh [3071:0];
-       reg [7:0] tiledatalow [3071:0];
+       reg [7:0] tiledatahigh [6143:0];
+       reg [7:0] tiledatalow [6143:0];
        reg [7:0] bgmap1 [1023:0];
        reg [7:0] bgmap2 [1023:0];
        
@@ -146,14 +146,19 @@ module LCDC(
        // The new tile data is latched and ready when vxpos[2:0] is 3'b000!
        wire [7:0] vxpos_ = vxpos + 1;
        wire [9:0] bgmapaddr = {vypos[7:3], vxpos_[7:3]};
-       reg [7:0] tileno;
-       wire [10:0] tileaddr = {tileno, vypos[2:0]};
+       reg [7:0] tileno1;
+       reg [7:0] tileno2;
+       wire [7:0] tileno = rLCDC[3] ? tileno2 : tileno1;
+       wire [11:0] tileaddr =
+               {(rLCDC[4] ? {1'b0,tileno} : (9'b100000000 + {tileno[7],tileno})),
+               vypos[2:0]};
        reg [7:0] tilehigh, tilelow;
        wire [1:0] prepal = {tilehigh[7-vxpos[2:0]], tilelow[7-vxpos[2:0]]};
        assign pixdata = 2'b11-{rBGP[{prepal,1'b1}],rBGP[{prepal,1'b0}]};
        
        wire decode_tiledata = (addr >= 16'h8000) && (addr <= 16'h97FF);
        wire decode_bgmap1 = (addr >= 16'h9800) && (addr <= 16'h9BFF);
+       wire decode_bgmap2 = (addr >= 16'h9C00) && (addr <= 16'h9FFF);
 
        wire [9:0] bgmapaddr_in = vraminuse ? bgmapaddr : addr[9:0];
        wire [11:0] tileaddr_in = vraminuse ? tileaddr : addr[12:1];
@@ -161,10 +166,15 @@ module LCDC(
        always @(posedge clk)
        begin
                if ((vraminuse && ((posx == 2) || (vxpos[2:0] == 3'b111))) || decode_bgmap1) begin
-                       tileno <= bgmap1[bgmapaddr_in];
+                       tileno1 <= bgmap1[bgmapaddr_in];
                        if (wr && decode_bgmap1 && ~vraminuse)
                                bgmap1[bgmapaddr_in] <= data;
                end
+               if ((vraminuse && ((posx == 2) || (vxpos[2:0] == 3'b111))) || decode_bgmap2) begin
+                       tileno2 <= bgmap2[bgmapaddr_in];
+                       if (wr && decode_bgmap2 && ~vraminuse)
+                               bgmap2[bgmapaddr_in] <= data;
+               end
                if ((vraminuse && ((posx == 3) || (vxpos[2:0] == 3'b000))) || decode_tiledata) begin
                        tilehigh <= tiledatahigh[tileaddr_in];
                        tilelow <= tiledatalow[tileaddr_in];