true dual port RAM

Thanks for your answers.

Here is the version of my code which works in Modelsim but not in Quartus. In Quartus, the Ram is not infered.

LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.ALL;
 
ENTITY ram512x36 IS
 PORT
 (
  address_a  : IN STD_LOGIC_VECTOR (8 DOWNTO 0);
  address_b  : IN STD_LOGIC_VECTOR (8 DOWNTO 0);
  clock  : IN STD_LOGIC ;
  data_a  : IN STD_LOGIC_VECTOR (35 DOWNTO 0);
  data_b  : IN STD_LOGIC_VECTOR (35 DOWNTO 0);
  wren_a  : IN STD_LOGIC:='1' ;
  wren_b  : IN STD_LOGIC:='1' ;
  q_a  : OUT STD_LOGIC_VECTOR (35 DOWNTO 0):="000000000000000000000000000000000000";
  q_b  : OUT STD_LOGIC_VECTOR (35 DOWNTO 0):="000000000000000000000000000000000000"
 );
END ram512x36;
LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.ALL;
ARCHITECTURE SYN OF ram512x36 IS
Type mem_tram_type is array (0 to 511) of std_logic_vector(35 downto 0);
signal dpram_mem_trame : mem_tram_type:=(others => (others =>'0'));
attribute block_ram : boolean;
attribute block_ram of dpram_mem_trame : signal is true;
signal w_q_a : STD_LOGIC_VECTOR (35 DOWNTO 0):="000000000000000000000000000000000000";
signal w_q_b : STD_LOGIC_VECTOR (35 DOWNTO 0):="000000000000000000000000000000000000";
 
begin
 
------------------------------------------------------------------------
-----------------------------------
process(clock)
-----------------------------------
begin
if clock'event and clock='1' then
 if wren_a='1' then
  q_a <= dpram_mem_trame(conv_integer(unsigned(address_a))) ;
  dpram_mem_trame(conv_integer(unsigned(address_a))) <= data_a;
 else
  q_a <= dpram_mem_trame(conv_integer(unsigned(address_a))) ;
 end if;
 
 if wren_b='1' then
  q_b <= dpram_mem_trame(conv_integer(unsigned(address_b))) ;
  dpram_mem_trame(conv_integer(unsigned(address_b))) <= data_b;
 else
  q_b <= dpram_mem_trame(conv_integer(unsigned(address_b))) ;
 end if;
 
end if;
 
-----------------------------------
end process;
-----------------------------------
 
 
END SYN;
 

I do not want to use megawizard functions.

Even if it does not work on modelsim, but is ok on quartus, it is what I want. I just want it to work on the board.

I 'm going to check if I have U or X. Yes I am using a testbench etc...