ASSERT statement using & operator

Altera_Forum · ‎08-24-2013

Hi,

Please consider the following code:


library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use work.my_package.all;
entity my_mux is
   generic(N: integer := 8);
   port(x:  in std_logic_vector(N-1 downto 0);
        a:  in std_logic_vector(ceil_log2(N)-1 downto 0);
         y: out std_logic);
end my_mux;
architecture arch of my_mux is
begin
   aviso: assert false
        report "size of a is " & a'length
        severity note;
             
   gen: for i in 0 to N-1 generate
             y <= x(i) when (a = std_logic_vector(to_unsigned(i, ceil_log2(N))) and (i < (N-1))) else
                   'Z';
   end generate;
end arch;

Regarding the line "report", I can´t synthesize this code. It is produced an error.

Everything like report "message 1" & "message 2" (considering messages 1 and 2 only text messages) it synthesizes well and produces me the desired note message.

If I try report "message" & xxxx, where xxxx is N, a'length, or any value different than a simple text, it produces an error.

error (10327): vhdl error at mux.vhd(18): can't determine definition of operator ""&"" -- found 0 possible definitions

How can I see my desired message?

Regards

Jaraqui

Altera_Forum · ‎08-24-2013

it is because "size of a is" is a string, and a'length is an integer type. You cannot concatenate them directly. You have to convert the integer to a string.

try this:


aviso: assert false
        report "size of a is " & integer'image(a'length)
        severity note;

Altera_Forum · ‎08-24-2013

perfect! Thanks!