How to Infer a ROM's Contents from a file? - How to Infer a ROM's Contents from a file? I'm trying to convert a Xilinx design onto a Cyclone V and am struggling with the Intel documentation on how to infer a ROM where its contents are provided by an external mif file. Looking at the documentation this idea does not seem to be covered. (i.e. the examples all appear to generate the ROM contents within the hdl files) Here is a snippet from the code I am trying to re-use: impure function init_mem(mif_file_name : in string) return T_ROM_TYPE is file mif_file : text open read_mode is mif_file_name; variable mif_line : line; variable temp_bv : std_logic_vector(G_DATA_WIDTH-1 downto 0); variable temp_mem : T_ROM_TYPE; begin for i in T_ROM_TYPE'range loop readline(mif_file, mif_line); hread(mif_line, temp_bv); temp_mem(i) := temp_bv; end loop; return temp_mem; end function; -- ROM array constant constant rom : T_ROM_TYPE := init_mem(G_ROM_INIT_DATA); begin ------------------------------------------------------------------------------- -- ROM read access control ------------------------------------------------------------------------------- rom_cotrol_proc : process (CLK) variable address : integer range 0 to ((2**G_ADDR_WIDTH)-1); begin if CLK'event and CLK = '1' then if IP_EN = '1' then address := to_integer(unsigned(IP_ADDR((G_ADDR_WIDTH-1) downto 0))); OP_DATA <= rom(address); end if; end if; end process; Replies: Re: How to Infer a ROM's Contents from a file? Thanks for the answers! Looks like I'll try the mega function where I can at least setup the ROM dimensions/contents via generics. Replies: Re: How to Infer a ROM's Contents from a file? You could initialize the memory using MIF file or Intel HEX file. I would suggest you replace your ROM code with one of Intel's 1-port ROM Megafunctions. When you use the megafunctions, there's an option to initialize the memory using MIF or HEX files. Migrating the small ROM/RAMs to using Intel megafunctions may help resolving such issues. -Abraham Replies: Re: How to Infer a ROM's Contents from a file? Unfortunately, Quartus has been lacking the ability to infer the ram contents using textio for years - I raised an enhancement request on this 10 years ago - afaik this is still not possible!!!! You can use the ram_init_file attribute to read the contents of a .mif file during synthesis, but it wont load it during simulation. The only way to load it during simulation is with an init function (like the one you posted - but this only would need to be removed from synthesis) or by using the altsyncram megafunction and specifying an init_file generic to the .mif file