ファイル名: simple_dual_one_clock.vhd
-- Simple Dual-Port Block RAM with One Clock
-- Correct Modelization with a Shared Variable
-- File:simple_dual_one_clock.vhd
library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;
entity simple_dual_one_clock is
port(
clk : in std_logic;
ena : in std_logic;
enb : in std_logic;
wea : in std_logic;
addra : in std_logic_vector(9 downto 0);
addrb : in std_logic_vector(9 downto 0);
dia : in std_logic_vector(15 downto 0);
dob : out std_logic_vector(15 downto 0)
);
end simple_dual_one_clock;
architecture syn of simple_dual_one_clock is
type ram_type is array (1023 downto 0) of std_logic_vector(15 downto 0);
shared variable RAM : ram_type;
begin
process(clk)
begin
if clk'event and clk = '1' then
if ena = '1' then
if wea = '1' then
RAM(conv_integer(addra)) := dia;
end if;
end if;
end if;
end process;
process(clk)
begin
if clk'event and clk = '1' then
if enb = '1' then
dob <= RAM(conv_integer(addrb));
end if;
end if;
end process;
end syn;