MacPlus_MiSTer/sys/gamma_corr.sv
2021-03-20 18:34:40 +08:00

125 lines
3.1 KiB
Systemverilog

module gamma_corr
(
input clk_sys,
input clk_vid,
input ce_pix,
input gamma_en,
input gamma_wr,
input [9:0] gamma_wr_addr,
input [7:0] gamma_value,
input HSync,
input VSync,
input HBlank,
input VBlank,
input [23:0] RGB_in,
output reg HSync_out,
output reg VSync_out,
output reg HBlank_out,
output reg VBlank_out,
output reg [23:0] RGB_out
);
(* ramstyle="no_rw_check" *) reg [7:0] gamma_curve[768];
always @(posedge clk_sys) if (gamma_wr) gamma_curve[gamma_wr_addr] <= gamma_value;
always @(posedge clk_vid) gamma <= gamma_curve[gamma_index];
reg [9:0] gamma_index;
reg [7:0] gamma;
always @(posedge clk_vid) begin
reg [7:0] R_in, G_in, B_in;
reg [7:0] R_gamma, G_gamma;
reg hs,vs,hb,vb;
reg [1:0] ctr = 0;
reg old_ce;
old_ce <= ce_pix;
if(~old_ce & ce_pix) begin
{R_in,G_in,B_in} <= RGB_in;
hs <= HSync; vs <= VSync;
hb <= HBlank; vb <= VBlank;
RGB_out <= gamma_en ? {R_gamma,G_gamma,gamma} : {R_in,G_in,B_in};
HSync_out <= hs; VSync_out <= vs;
HBlank_out <= hb; VBlank_out <= vb;
ctr <= 1;
gamma_index <= {2'b00,RGB_in[23:16]};
end
if (|ctr) ctr <= ctr + 1'd1;
case(ctr)
1: begin gamma_index <= {2'b01,G_in}; end
2: begin R_gamma <= gamma; gamma_index <= {2'b10,B_in}; end
3: begin G_gamma <= gamma; end
endcase
end
endmodule
module gamma_fast
(
input clk_vid,
input ce_pix,
inout [21:0] gamma_bus,
input HSync,
input VSync,
input HBlank,
input VBlank,
input DE,
input [23:0] RGB_in,
output reg HSync_out,
output reg VSync_out,
output reg HBlank_out,
output reg VBlank_out,
output reg DE_out,
output reg [23:0] RGB_out
);
(* ramstyle="no_rw_check" *) reg [7:0] gamma_curve_r[256];
(* ramstyle="no_rw_check" *) reg [7:0] gamma_curve_g[256];
(* ramstyle="no_rw_check" *) reg [7:0] gamma_curve_b[256];
assign gamma_bus[21] = 1;
wire clk_sys = gamma_bus[20];
wire gamma_en = gamma_bus[19];
wire gamma_wr = gamma_bus[18];
wire [9:0] gamma_wr_addr = gamma_bus[17:8];
wire [7:0] gamma_value = gamma_bus[7:0];
always @(posedge clk_sys) if (gamma_wr) begin
case(gamma_wr_addr[9:8])
0: gamma_curve_r[gamma_wr_addr[7:0]] <= gamma_value;
1: gamma_curve_g[gamma_wr_addr[7:0]] <= gamma_value;
2: gamma_curve_b[gamma_wr_addr[7:0]] <= gamma_value;
endcase
end
reg [7:0] gamma_index_r,gamma_index_g,gamma_index_b;
always @(posedge clk_vid) begin
reg [7:0] R_in, G_in, B_in;
reg [7:0] R_gamma, G_gamma;
reg hs,vs,hb,vb,de;
if(ce_pix) begin
{gamma_index_r,gamma_index_g,gamma_index_b} <= RGB_in;
hs <= HSync; vs <= VSync;
hb <= HBlank; vb <= VBlank;
de <= DE;
RGB_out <= gamma_en ? {gamma_curve_r[gamma_index_r],gamma_curve_g[gamma_index_g],gamma_curve_b[gamma_index_b]}
: {gamma_index_r,gamma_index_g,gamma_index_b};
HSync_out <= hs; VSync_out <= vs;
HBlank_out <= hb; VBlank_out <= vb;
DE_out <= de;
end
end
endmodule