Synthesizing process does not stop

[Drashti Patel]

hi every one,
I am working on xilinx 14.1.
I am trying to read a text file containing 16384 binary data(each of 10 bits) and store it in to RAM.
As I execute following code, and tries to synthesize it, the synthesizing process keeps running and it never stops.

console block shows the comment :
Elaborating entity <win_test> (architecture <bev&gt from library <work>.
Non-constant loop found; will execute up to 5000 iterations


library IEEE;
use IEEE.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_textio.all;
use std.textio.all;
entity win_test is
port (address : in std_logic_vector(14 downto 0);
dataout : out std_logic_vector(9 downto 0));
end entity;

architecture bev of win_test is

type mem is array (0 to 16384) of std_logic_vector(9 downto 0);
signal t_mem : mem;
begin
process(address)
FILE f : TEXT;
constant filename : string :="win_data - Copy.txt";
VARIABLE L : LINE;
variable i : integer:=0;
variable b : std_logic_vector(9 downto 0);
begin

File_Open (f,FILENAME, read_mode);
while ((i<=16384) and (not EndFile (f))) loop
readline (f, l);
next when l(1) = '#'; -- to read first line
read(l, b);
t_mem(i) <= b;
i := i + 1;
end loop;
File_Close (f);
dataout<=t_mem(conv_integer(address));
end process;
end bev;


When I tried the same code to read file containing smaller number of data(16 instead of 16384), the code synthesized successfully.

Please help me with this.

 

[GaborSzakacs]

Drashti Patel wrote:

hi every one,
I am working on xilinx 14.1.
I am trying to read a text file containing 16384 binary data(each of 10 bits) and store it in to RAM.
As I execute following code, and tries to synthesize it, the synthesizing process keeps running and it never stops.

console block shows the comment :
Elaborating entity <win_test> (architecture <bev&gt from library <work>.
Non-constant loop found; will execute up to 5000 iterations


library IEEE;
use IEEE.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_textio.all;
use std.textio.all;
entity win_test is
port (address : in std_logic_vector(14 downto 0);
dataout : out std_logic_vector(9 downto 0));
end entity;

architecture bev of win_test is

type mem is array (0 to 16384) of std_logic_vector(9 downto 0);
signal t_mem : mem;
begin
process(address)
FILE f : TEXT;
constant filename : string :="win_data - Copy.txt";
VARIABLE L : LINE;
variable i : integer:=0;
variable b : std_logic_vector(9 downto 0);
begin

File_Open (f,FILENAME, read_mode);
while ((i<=16384) and (not EndFile (f))) loop
readline (f, l);
next when l(1) = '#'; -- to read first line
read(l, b);
t_mem(i) <= b;
i := i + 1;
end loop;
File_Close (f);
dataout<=t_mem(conv_integer(address));
end process;
end bev;


When I tried the same code to read file containing smaller number of data(16 instead of 16384), the code synthesized successfully.

Please help me with this.

"Non-constant loop found; will execute up to 5000 iterations"

This may be a problem. I don't know if ISE has an option to increase
the maximum iteration limit. One possible workaround is to make sure
your file is at least 16K lines, and remove the "and (not Endfile (f))"
from the loop condition to see if using a constant loop allows more
iterations.

--
Gabor