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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity dpram4 is
port (raddr : std_logic_vector (3 downto 0);
rdat : out std_logic_vector (7 downto 0);
waddr : std_logic_vector (3 downto 0);
wdat : std_logic_vector (7 downto 0);
rclk : std_logic;
wclk : std_logic);
end;
architecture behav of dpram4 is
subtype memtype is std_logic_vector (16 * 8 - 1 downto 0);
begin
process (rclk, wclk)
variable ra : natural;
variable wa : natural;
variable mem : memtype;
begin
if rising_edge (rclk) then
ra := to_integer(unsigned (raddr));
rdat <= mem (ra * 8 + 7 downto ra * 8);
end if;
if rising_edge(wclk) then
wa := to_integer(unsigned (waddr));
mem (wa * 8 + 7 downto wa * 8) := wdat;
end if;
end process;
end behav;
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