Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

[ERROR]"Can't resolve multiple constant drivers for net ......."

Hello,

It's my first time wriring in VHDL language ,so do not be offended by the potential mistakes I could have made.

My problem is as following ,I created process describing one of the states.This process i responsible for initializng two blank tables.

The process is as following: 

	process(start_sygnal, clk)
	begin
		if clk'event and clk = '1' then
			if start_sygnal = '1' then
				gra_Tablica(0) <=   (   x"00000000000000000000000000000000", 
							        x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000",
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000");
				gra_Tablica(1) <= (   x"00000000000000000000000000000000", 
							        x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000",
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000", 
									x"00000000000000000000000000000000");
				
				wykonano_start_sygnal <= '1';
			else
				wykonano_start_sygnal <= '0';
			end if;
		end if;
	end process;

Unfortunatley i got constatnt error form compiler f.i :

"Error (10028): Can't resolve multiple constant drivers for net "gra_Tablica[1][63][125]" at a.vhd(541)"

How do solve this matter

Thansk in advance

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    I guess, the conflict is from concurrent assignment in another process, that isn't shown in the posting, also the array definition is unknown. If you have concurrent assignments to registers, they have to reside in one process to allow the compiler to resolve the access.

    B.T.W., I wonder which Quartus version your are using, mine has no capital letter ERROR messages.

    The initialisation could be achieved more comfortable (and better readable) by 

    gra_Tablica(0) <=  (OTHERS =>(OTHERS => '0')); 
--or probably
gra_Tablica <=  (OTHERS =>(OTHERS =>(OTHERS => '0')));