Initializing Block RAM (VHDL) - 2024.1 English

Vivado Design Suite User Guide: Synthesis (UG901)

Document ID
Release Date
2024.1 English

Filename: rams_sp_rom.vhd

-- Initializing Block RAM (Single-Port Block RAM)
-- File: rams_sp_rom.vhd
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity rams_sp_rom is
clk : in std_logic;
we : in std_logic;
addr : in std_logic_vector(5 downto 0);
di : in std_logic_vector(19 downto 0);
do : out std_logic_vector(19 downto 0)
end rams_sp_rom;

architecture syn of rams_sp_rom is
type ram_type is array (63 downto 0) of std_logic_vector(19 downto 0);
signal RAM : ram_type := (X"0200A", X"00300", X"08101", X"04000", X"08601", X"0233A",
X"00300", X"08602", X"02310", X"0203B", X"08300", X"04002",
X"08201", X"00500", X"04001", X"02500", X"00340", X"00241",
X"04002", X"08300", X"08201", X"00500", X"08101", X"00602",
X"04003", X"0241E", X"00301", X"00102", X"02122", X"02021",
X"00301", X"00102", X"02222", X"04001", X"00342", X"0232B",
X"00900", X"00302", X"00102", X"04002", X"00900", X"08201",
X"02023", X"00303", X"02433", X"00301", X"04004", X"00301",
X"00102", X"02137", X"02036", X"00301", X"00102", X"02237",
X"04004", X"00304", X"04040", X"02500", X"02500", X"02500",
X"0030D", X"02341", X"08201", X"0400D");

if rising_edge(clk) then
if we = '1' then
RAM(to_integer(unsigned(addr))) <= di;
end if;
do <= RAM(to_integer(unsigned(addr)));
end if;
end process;

end syn;