Files
vhdl/lib/misc/ram_wb.vhd
T
jens 69697d7222 - Intital revision
git-svn-id: http://moon:8086/svn/vhdl/trunk@86 cc03376c-175c-47c8-b038-4cd826a8556b
2008-10-20 19:26:01 +00:00

81 lines
1.3 KiB
VHDL

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.NUMERIC_STD.ALL;
ENTITY ram_wb IS
Port
(
CLK_I : in STD_LOGIC;
RST_I : in STD_LOGIC;
CYC_I : in STD_LOGIC;
STB_I : in STD_LOGIC;
SEL_I : in unsigned(3 downto 0);
WE_I : in STD_LOGIC;
ACK_O : out STD_LOGIC;
SRDY_O : out STD_LOGIC;
MRDY_I : in STD_LOGIC;
ADDR_I : in unsigned(31 downto 0);
DAT_I : in unsigned(31 downto 0);
DAT_O : out unsigned(31 downto 0)
);
END ram_wb;
ARCHITECTURE behavior OF ram_wb IS
COMPONENT ram
GENERIC
(
word_addr_width : integer
);
PORT
(
clk : in STD_LOGIC;
ce : in STD_LOGIC;
we : in unsigned(3 downto 0);
addr : in unsigned(31 downto 0);
din : in unsigned(31 downto 0);
dout : out unsigned(31 downto 0)
);
END COMPONENT;
signal data_en : std_logic;
signal we : unsigned(3 downto 0);
begin
we <= SEL_I and (3 downto 0 => WE_I);
data_en <= CYC_I and STB_I and MRDY_I;
SRDY_O <= CYC_I;
data_valid_register:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if RST_I = '1' then
ACK_O <= '0';
else
ACK_O <= data_en and not WE_I;
end if;
end if;
end process;
inst_ram : ram
GENERIC MAP
(
word_addr_width => 6
)
PORT MAP
(
clk => CLK_I,
ce => data_en,
we => we,
addr => ADDR_I,
din => DAT_I,
dout => DAT_O
);
end behavior;