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NES: mapper 30: fix Twin Dragons graphical corruption

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Author: Cray Elliott <MP2E@archlinux.us>
This commit is contained in:
Gyorgy Szombathelyi
2020-02-18 13:38:13 +01:00
parent f3416fe71c
commit 8fa561da55
1 changed files with 13 additions and 13 deletions
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26
cores/nes/src/mappers/generic.sv
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@@ -161,35 +161,35 @@ reg [15:0] flags_out = 0;
reg [4:0] prgbank;
reg [1:0] chrbank;
reg [2:0] mirror;
wire four_screen = (mirror[2:1] == 2'b11);
reg nametable;
wire four_screen = flags[16] && flags[14];
always @(posedge clk) begin
if (~enable) begin
// Set value for mirroring
mirror[2:1] <= {flags[16], flags[14]};
prgbank <= 0;
chrbank <= 0;
nametable <= 0;
end else if (ce) begin
if (prg_ain[15] & prg_write) begin
{mirror[0], chrbank, prgbank} <= prg_din[7:0];
{nametable, chrbank, prgbank} <= prg_din[7:0];
end
end
end
always begin
// mirroring mode
casez({mirror[2:1],chr_ain[13]})
3'b001 : vram_a10 = {chr_ain[11]}; // horizontal
3'b011 : vram_a10 = {chr_ain[10]}; // vertical
3'b101 : vram_a10 = {mirror[0]}; // 1 screen
3'b111 : vram_a10 = {chr_ain[10]}; // 4 screen
default : vram_a10 = {chr_ain[10]}; // pattern table
casez({flags[16], flags[14]})
3'b00 : vram_a10 = chr_ain[11]; // horizontal
3'b01 : vram_a10 = chr_ain[10]; // vertical
3'b10 : vram_a10 = nametable; // 1 screen
default : vram_a10 = chr_ain[10]; // 4 screen
endcase
end
assign prg_aout = {3'b000, prg_ain[14] ? 5'b11111 : prgbank, prg_ain[13:0]};
assign prg_aout = {3'b000, (prg_ain[15:14] == 2'b11) ? 5'b11111 : prgbank, prg_ain[13:0]};
assign prg_allow = prg_ain[15] && !prg_write;
assign chr_allow = flags[15];
assign chr_aout = {flags[15] ? 7'b11_1111_1 : 7'b10_0000_0, (four_screen && (chr_ain[13])) ? 2'b11 : chrbank, chr_ain[12:11], vram_a10, chr_ain[9:0]};
assign chr_aout = {flags[15] ? 7'b11_1111_1 : 7'b10_0000_0, (four_screen && chr_ain[13]) ? 2'b11 : chrbank, chr_ain[12:0]};
assign vram_ce = chr_ain[13] && !four_screen;
endmodule