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

VHDL problem

Hi everyone,

I'm a new user of FPGA.

I have 2 LEDs and a clock of 32KHz.

So I wanna light up LED1

then light off LED 1 and light up LED2.

Im trying to do something in VHDL, but it seems it's nonsense what I've done

LIBRARY ieee;

USE ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use IEEE.STD_LOGIC_SIGNED;

use IEEE.STD_LOGIC_UNSIGNED;

use IEEE.STD_LOGIC_ARITH.ALL;

ENTITY TP4LED IS

PORT (

clock : IN std_logic;

s1: OUT std_logic;

s2: OUT std_logic

);

END TP4LED;

ARCHITECTURE behavior OF TP4LED IS -- fonctionnement d'une bascule D

signal count : integer(10 downto 0);

BEGIN

PROCESS (clock) -- liste de sensibilité

BEGIN

count <= '0';

s1<='1';

s2<='0';

if(clock'event and clock='1')then

count <= count + 1;

if (count = '9') then

s1<='0';

s2<='1';

count<=0;

end if;

end if;

END PROCESS;

END behavior;

In addition, I have this mistake that I don't know how to resolve it

Error (10380): VHDL error at TP4LED.vhd(24): integer type is used but not declared as an array type

I know it might be an easy question. Could anyone help me please

thank you very much

Bo

1 Reply

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

    integer is not an array type, so you cannot use it like and array. Your count signal declaration says you want 11 integers. If you wanted a single integer with 11 bits, you should use the unsigned type (before you do this - delete the non-standard std_logic_unsigned/signed and std_logic_arith libraries from your library list - otherwise you're going to get all sorts of conflicts).

    You need:

    signal count : unsigned(10 downto 0);

    secondly, '9' is a character, not an integer value. change it to

    if count = 9 then...

    Finally, do not do assignments outside of the clocked part of the process.