Hi
For my project, i need to implement a ROM component that stores routing order information. I have "designed" the ROM from ISE example in such a way that the ROM size can be increased depending on the size of the table order it needs to store.
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity ROM is
generic(
ADDR_BITS : integer :=3;
BITS : integer :=3
);
port(
CLK : in std_logic;
EN : in std_logic;
ADDR : in std_logic_vector(ADDR_BITS-1 downto 0);
DATA : out std_logic_vector(BITS-1 downto 0)
);
end ROM;
architecture rtl of ROM is
type rom_type is array (0 to 2**ADDR_BITS-1) of std_logic_vector(BITS-1 downto 0);
signal ROM : rom_type :=
(
"000", "001", "010", "011","100","101","110","111" --0,1,2,3,4,5,6,7 the routing order
);
signal rdata : std_logic_vector(BITS-1 downto 0);
begin
rdata <= ROM(conv_integer(ADDR));
process (CLK)
begin
if (CLK'event and CLK = '1') then
if (EN = '1') then
DATA <= rdata;
end if;
end if;
end process;
end rtl;
On Xilinx Platform Studio (XPS), i generated the IP design and the following MPD file is what "describes" the ROM :
BEGIN ROM
## Peripheral Options
OPTION IPTYPE = PERIPHERAL
OPTION IMP_NETLIST = TRUE
OPTION HDL = MIXED
OPTION IP_GROUP = USER
## Bus Interfaces
## Generics for VHDL or Parameters for Verilog
PARAMETER ADDR_BITS = 3, DT = INTEGER
PARAMETER BITS = 3, DT = INTEGER
## Ports
PORT CLK = "", DIR = I
PORT EN = "", DIR = I
PORT ADDR = "", DIR = I, VEC = [(ADDR_BITS-1):0], ENDIAN = LITTLE
PORT DATA = "", DIR = O, VEC = [(BITS-1):0], ENDIAN = LITTLE
END
The problem that i can't figure out is how to code the ROM (both the vhd and the mpd) in such a way that when on XPS i need to add 2 or more instances of the same ROM, i can change the content of the ROMs...there will be cases when i need more than 1 instance and the content is not the same, both length and order. F.ex. lets say i need 2 ROMs, the first one will have an addr size of 8, thus i need to enter 8 different values (values can be either int, std_logic_vector) and the second ROM will have an addr_size of 14. In the vhd example above i have hardcoded the values for testing purposes, but they need to be defined when i add the ROM(s) on XPS.
For the project purposes is enough if i have to enter the content manually everytime i add an instance of ROM, so if anyone can help or have suggestions pls let me know ASAP.
