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diff --git a/basys3/basys3.srcs/ppu_addr_dec.vhd b/basys3/basys3.srcs/ppu_addr_dec.vhd
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+library ieee;
+library work;
+use ieee.std_logic_1164.all;
+--use ieee.numeric_std.all;
+use work.ppu_consts.all;
+
+entity ppu_addr_dec is port(
+ EN: in std_logic; -- EXT *ADDR enable (switch *AO to ADDR instead of *AI)
+ WEN: in std_logic; -- EXT write enable
+ TMM_WEN,
+ BAM_WEN,
+ FAM_WEN,
+ PAL_WEN,
+ AUX_WEN: out std_logic; -- write enable MUX
+ ADDR: in std_logic_vector(PPU_RAM_BUS_ADDR_WIDTH-1 downto 0); -- address in
+ TMM_AI: in std_logic_vector(PPU_TMM_ADDR_WIDTH-1 downto 0);
+ BAM_AI: in std_logic_vector(PPU_BAM_ADDR_WIDTH-1 downto 0);
+ FAM_AI: in std_logic_vector(PPU_FAM_ADDR_WIDTH-1 downto 0);
+ PAL_AI: in std_logic_vector(PPU_PAL_ADDR_WIDTH-1 downto 0);
+ AUX_AI: in std_logic_vector(PPU_AUX_ADDR_WIDTH-1 downto 0);
+ TMM_AO: out std_logic_vector(PPU_TMM_ADDR_WIDTH-1 downto 0);
+ BAM_AO: out std_logic_vector(PPU_BAM_ADDR_WIDTH-1 downto 0);
+ FAM_AO: out std_logic_vector(PPU_FAM_ADDR_WIDTH-1 downto 0);
+ PAL_AO: out std_logic_vector(PPU_PAL_ADDR_WIDTH-1 downto 0);
+ AUX_AO: out std_logic_vector(PPU_AUX_ADDR_WIDTH-1 downto 0));
+end ppu_addr_dec;
+
+architecture Behavioral of ppu_addr_dec is
+ signal TMM_RANGE, BAM_RANGE, FAM_RANGE, PAL_RANGE, AUX_RANGE: std_logic := '0'; -- ADDR in range of memory area
+begin
+ -- address MUX
+ TMM_AO <= ADDR(PPU_TMM_ADDR_WIDTH-1 downto 0) when EN = '1' else TMM_AI;
+ BAM_AO <= ADDR(PPU_BAM_ADDR_WIDTH-1 downto 0) when EN = '1' else BAM_AI;
+ FAM_AO <= ADDR(PPU_FAM_ADDR_WIDTH-1 downto 0) when EN = '1' else FAM_AI;
+ PAL_AO <= ADDR(PPU_PAL_ADDR_WIDTH-1 downto 0) when EN = '1' else PAL_AI;
+ AUX_AO <= ADDR(PPU_AUX_ADDR_WIDTH-1 downto 0) when EN = '1' else AUX_AI;
+
+ -- WEN MUX
+ TMM_WEN <= TMM_RANGE and WEN;
+ BAM_WEN <= BAM_RANGE and WEN;
+ FAM_WEN <= FAM_RANGE and WEN;
+ PAL_WEN <= PAL_RANGE and WEN;
+ AUX_WEN <= AUX_RANGE and WEN;
+
+ -- address ranges
+ TMM_RANGE <= '1' when not (ADDR(15) = '1' and ADDR(14) = '1') else '0';
+ BAM_RANGE <= '1' when (ADDR(15) = '1' and ADDR(14) = '1') and (ADDR(11) = '0') else '0';
+ FAM_RANGE <= '1' when (ADDR(15) = '1' and ADDR(14) = '1') and (ADDR(11) = '1' and ADDR(10) = '0') else '0';
+ PAL_RANGE <= '1' when (ADDR(15) = '1' and ADDR(14) = '1') and (ADDR(11) = '1' and ADDR(10) = '1' and ADDR(9) = '0') else '0';
+ AUX_RANGE <= '1' when (ADDR(15) = '1' and ADDR(14) = '1') and (ADDR(11) = '1' and ADDR(10) = '1' and ADDR(9) = '1') else '0';
+end Behavioral;