check columns in a matrix

flex schrieb:
> with this check i want to make sure that every column in the matrix
> doesn't have more than one '1'.
Try this:

1

signal fail : std_logic;

2

3

process (matrix) 

4

signal one : std_logic;

5

begin

6

   fail <= '0';

7

   for c in 0 to 7 loop

8

      one := '0';

9

      for r in 1 to 5 loop

10

         if (matrix(r,c)='1') then -- or   matric (r)(c)  depends on definition of matrix

11

            if one='1' then

12

               fail <= '1';

13

            -- exit;               -- maybe this helps saving ressources

14

            end if;

15

            one := '1';

16

         end if;

17

      end loop;

18

   end loop;

19

end process;

BTW: why does the row count of your matrix start with number 1?
But what do you want to do, if theres more than one '1'?

no_name schrieb:
> i didnt check exactly the code u write. but thers is 2 for loops.
> that needs a lot of resources.
How du you result in this conclusion? Did you test or try it?

> this is my process:
Hmmm...  You describe a latch (gated by a bunch of signals). This is no 
good design practice...
For writing in the array you should use a clock. Thats the way flipflops 
inside the FPGA are built: they use a clock to store data.

I dont think so...

Just as a hint: what type is this?
  matrix(0 to 7)(i)

I'm not able to determine it just from the scratch...


BTW
Even if this process would work, you could trim it this way without any 
loss of funtionality:

1

control : process(matrix)

2

begin

3

  for i in 0 to 7 loop

4

     matrix(0 to 7)(i) <= (others => '0'); 

5

  end loop;

6

end process control;