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fiddled the vga module a little

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This commit is contained in:
Alan Garfield 2018-01-30 00:19:21 +11:00
parent 4fef9bc10b
commit 451bff1592
1 changed files with 44 additions and 17 deletions
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61
rtl/vga/vga.v
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@ -4,9 +4,9 @@ module vga(
input in_stb,
output vga_h_sync,
output vga_v_sync,
output reg vga_red,
output reg vga_grn,
output reg vga_blu
output vga_red,
output vga_grn,
output vga_blu
);
reg [5:0] v_ram[0:959] /* synthesis syn_ramstyle = "block_ram" */;
@ -94,28 +94,55 @@ module vga(
end
end
reg out;
assign vga_red = out;
assign vga_grn = out;
assign vga_blu = out;
always @(posedge clk25)
begin
if (~(vga_h_act && vga_v_act))
begin
// outside display area
vga_red = 0;
case ({vga_h_act, vga_v_act})
default:
begin
// outside display area
out = 1'b0;
end
end else begin
// inside display area
2'b11:
begin
// inside display frame
case (vdot)
5'b00000,
5'b00001,
5'b00010,
5'b00011,
5'b10010,
5'b10011:
// blank row for spacing
out = 1'b0;
if (vdot[4:1] == 0 || vdot[4:1] == 1 || vdot[4:1] == 9 || hdot[3:1] == 0 || hdot[3:1] == 6 || hdot[3:1] == 7)
vga_red = 0;
else
vga_red = c_rom[(v_ram[hpos + (vpos * 40)] * 7) + (vdot[4:1] - 2)][5 - hdot[3:1]];
default:
case (hdot)
4'b0000,
4'b0001,
4'b1100,
4'b1101,
4'b1110,
4'b1111:
// blank column for spacing
out = 1'b0;
end
vga_grn = vga_red;
vga_blu = vga_red;
default:
// into character pixels
// TODO: fix this mess
out = c_rom[(v_ram[hpos + (vpos * 40)] * 7) + (vdot[4:1] - 2)][5 - hdot[3:1]];
endcase
endcase
end
endcase
end
// FIXME: This is horrible
reg [5:0] cur_pos;
reg stb;
always @(posedge clk25)