[SOLVED] iteration limit reached after 1000 ps

Hi friends ,

I am having control line if I change that mux select line means at that time this error occurs.

iteration limit reached after 1000 ps.

If I change it in the 400th ps means it shows like

iteration limit reached after 400 ps..

Pls reply wat ll be the fault..

Thanks in advance...

Can you post the code here?

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;
entity bu2 is
port(ip_re,ip_im:in std_logic_vector(3 downto 0);
sel:in bit;
op_re,op_imut std_logic_vector(3 downto 0));
end bu2;
architecture bu of bu2 is
signal j,k,l,m,x,y,p,q,a,b,c:std_logic_vector(3 downto 0);
component mux is
port(a,b:in std_logic_vector(3 downto 0);
sel:in bit;
yut std_logic_vector(3 downto 0));
end component;
component twos_complement is
port(ain:in std_logic_vector(3 downto 0);
youtut std_logic_vector(3 downto 0));
end component;
begin
j<=(ip_re xor p);
k<=(ip_im xor q);
l<=(x xor ip_re);
m<=(y xor ip_im);
l0:twos_complement port map(x,p);
l1:twos_complement port map(y,q);
l2:mux port map(ip_re,j,sel,x);
l3:mux port map(ip_im,k,sel,y);
l4:mux port map(x,l,sel,a);
l5:mux port map(y,m,sel,b);
l6:mux port map(a,b,sel,op_re);
l7:twos_complement port map(a,c);
l8:mux port map(b,c,sel,op_im);
end bu;

It might be due to the combinatorial feedback path from I2/I3 thru I0/I1 thru j/k back to I2/I3.