1 files changed, 100 insertions, 0 deletions
diff --git a/basys3/basys3.srcs/ppu_aux_tb.vhd b/basys3/basys3.srcs/ppu_aux_tb.vhd
new file mode 100644
index 0000000..ab3db62
--- /dev/null
+++ b/basys3/basys3.srcs/ppu_aux_tb.vhd
@@ -0,0 +1,100 @@
+library ieee;
+library unisim;
+library work;
+
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+use unisim.vcomponents.all;
+use work.ppu_consts.all;
+
+entity ppu_aux_tb is
+end ppu_aux_tb;
+
+architecture behavioral of ppu_aux_tb is
+	component ppu_aux port(
+		CLK : in std_logic; -- system clock
+		RESET : in std_logic; -- reset memory
+
+		-- internal memory block (AUX)
+		AUX_WEN : in std_logic; -- VRAM AUX write enable
+		AUX_ADDR : in std_logic_vector(PPU_AUX_ADDR_WIDTH-1 downto 0); -- VRAM AUX address
+		AUX_DATA : in std_logic_vector(PPU_AUX_DATA_WIDTH-1 downto 0); -- VRAM AUX data
+		
+		-- aux outputs
+		BG_SHIFT_X : out std_logic_vector(PPU_POS_H_WIDTH-1 downto 0);
+		BG_SHIFT_Y : out std_logic_vector(PPU_POS_V_WIDTH-1 downto 0);
+		FG_FETCH : out std_logic);
+	end component;
+
+	signal CLK, RST, WEN : std_logic := '0';
+	signal ADDR : std_logic_vector(PPU_AUX_ADDR_WIDTH-1 downto 0) := (others => '0');
+	signal DATA : std_logic_vector(PPU_AUX_DATA_WIDTH-1 downto 0) := (others => '0');
+
+	signal BG_SHIFT_X : std_logic_vector(PPU_POS_H_WIDTH-1 downto 0);
+	signal BG_SHIFT_Y : std_logic_vector(PPU_POS_V_WIDTH-1 downto 0);
+	signal FG_FETCH : std_logic;
+begin
+	uut : component ppu_aux
+		port map(
+			CLK => CLK,
+			RESET => RST,
+			AUX_WEN => WEN,
+			AUX_ADDR => ADDR,
+			AUX_DATA => DATA,
+			BG_SHIFT_X => BG_SHIFT_X,
+			BG_SHIFT_Y => BG_SHIFT_Y,
+			FG_FETCH => FG_FETCH);
+
+	tb : process
+	begin
+		-- reset
+		RST <= '1';
+		wait for 5 ns;
+		RST <= '0';
+		wait for 5 ns;
+
+		WEN <= '1';
+		-- set BG_SHIFT_X to 178
+		-- set BG_SHIFT_Y to 39
+		-- set FG_FETCH to 1
+		ADDR(0) <= '0';
+		DATA <= x"b327";
+
+		CLK <= '1';
+		wait for 1 ns;
+		CLK <= '0';
+		wait for 1 ns;
+
+		ADDR(0) <= '1';
+		DATA <= x"0002";
+
+		CLK <= '1';
+		wait for 1 ns;
+		CLK <= '0';
+		wait for 1 ns;
+
+		wait for 5 ns;
+
+		-- set BG_SHIFT_X to 30
+		-- set BG_SHIFT_Y to 69
+		-- set FG_FETCH to 0
+		ADDR(0) <= '0';
+		DATA <= x"1e45";
+
+		CLK <= '1';
+		wait for 1 ns;
+		CLK <= '0';
+		wait for 1 ns;
+
+		ADDR(0) <= '1';
+		DATA <= x"0000";
+
+		CLK <= '1';
+		wait for 1 ns;
+		CLK <= '0';
+		wait for 1 ns;
+
+
+		wait; -- stop for simulator
+	end process;
+end;