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authorlonkaars <loek@pipeframe.xyz>2023-02-24 13:20:02 +0100
committerlonkaars <loek@pipeframe.xyz>2023-02-24 13:20:02 +0100
commitf3a47bde9bfaaa716de835c0c1499a685b4ac4f7 (patch)
tree90abe28726ea7484184179129256022472eb2e24 /basys3/basys3.srcs/ppu_vga_native.vhd
parent7da7908989686daa2ac9fd2f3f79cad2f03c0828 (diff)
parent14a1c464c27206bff847fd46d3d5594b30f53af9 (diff)
Merge branch 'dev' into ppu-interface
Diffstat (limited to 'basys3/basys3.srcs/ppu_vga_native.vhd')
-rw-r--r--basys3/basys3.srcs/ppu_vga_native.vhd95
1 files changed, 95 insertions, 0 deletions
diff --git a/basys3/basys3.srcs/ppu_vga_native.vhd b/basys3/basys3.srcs/ppu_vga_native.vhd
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+++ b/basys3/basys3.srcs/ppu_vga_native.vhd
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+library ieee;
+use ieee.std_logic_1164.all;
+use work.ppu_consts.all;
+use ieee.numeric_std.all;
+use ieee.std_logic_unsigned.all;
+
+entity ppu_vga_native is port (
+ CLK: in std_logic; -- system clock
+ RESET: in std_logic;
+
+ X: in std_logic_vector(PPU_POS_H_WIDTH-1 downto 0); -- current screen pixel x
+ Y: in std_logic_vector(PPU_POS_V_WIDTH-1 downto 0); -- current screen pixel y
+ PREADY: in std_logic; -- current pixel ready (pixel color is stable)
+ RI,GI,BI: in std_logic_vector(PPU_COLOR_OUTPUT_DEPTH-1 downto 0); -- VGA color in
+
+ RO,GO,BO: out std_logic_vector(PPU_COLOR_OUTPUT_DEPTH-1 downto 0); -- VGA color out
+ VSYNC, HSYNC: out std_logic); -- VGA sync outputs
+end ppu_vga_native;
+
+architecture Behavioral of ppu_vga_native is
+ type line_buffer is array(319 downto 0) of std_logic_vector(11 downto 0);
+ signal ram_x0 : line_buffer; -- buffer 0
+ signal ram_x1: line_buffer; -- buffer 1
+ signal hcount: std_logic_vector(9 downto 0):= (others => '0');
+ signal vcount: std_logic_vector(9 downto 0):= (others => '0');
+ signal clk_counter: std_logic_vector(1 downto 0):= (others => '0');
+ signal rgb_out : std_logic_vector(11 downto 0):= (others => '0'); -- output colors
+ signal px : integer; -- conversion for hcount
+ signal py :integer; -- conversion for vcount
+ signal buffer_filled_on_buffer0 : integer;
+ signal buffer_filled_on_buffer1 : integer;
+begin
+ process (clk, x, y)
+ variable v_x : integer; -- integer to hold vector X
+ begin
+ if rising_edge(clk) then
+ clk_counter <= clk_counter + 1;
+ if clk_counter = "11" then
+ v_x := to_integer(unsigned(x) - 72);
+ if v_x >= 0 and v_x < 320 and PREADY = '1' then
+ if y(0) = '0' then
+ ram_x0(v_x) <= RI & GI & BI;
+ if v_x = 319 then
+ buffer_filled_on_buffer0 <= to_integer(unsigned(y) - 14);
+ end if;
+ else
+ ram_x1(v_x) <= RI & GI & BI;
+ if v_x = 319 then
+ buffer_filled_on_buffer1 <= to_integer(unsigned(y) - 14);
+ end if;
+ end if;
+ end if;
+ -- T display(display data)
+ if (hcount >= 144) and (hcount < 784) and (vcount >= 31) and (vcount < 511) then
+ px <= to_integer(unsigned(hcount) - 144);
+ py <= to_integer(unsigned(vcount) - 31);
+ if buffer_filled_on_buffer0 = (py/2) then
+ rgb_out <= ram_x0(px/2);
+ elsif buffer_filled_on_buffer1 = (py/2) then
+ rgb_out <= ram_x1(px/2);
+ else
+ rgb_out <= (others => '0');
+ end if;
+ end if;
+ -- pulse width
+ hsync <= '1';
+ if hcount < 97 then
+ hsync <= '0';
+ end if;
+
+ vsync <= '1';
+ if vcount < 3 then
+ vsync <= '0';
+ end if;
+
+ -- sync pulse time
+ hcount <= hcount + 1;
+
+ if hcount = 800 then
+ vcount <= vcount + 1;
+ hcount <= (others => '0');
+ end if;
+
+ if vcount = 521 then
+ vcount <= (others => '0');
+ end if;
+ end if;
+
+ -- output colors
+ RO <= rgb_out(11 downto 8);
+ GO <= rgb_out(7 downto 4);
+ BO <= rgb_out(3 downto 0);
+ end if;
+ end process;
+end Behavioral;