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Altera_Forum
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16 years ago

Counter.. Having problems adding? Please help!

LIBRARY IEEE;

USE IEEE.STD_LOGIC_1164.all;

USE IEEE.STD_LOGIC_UNSIGNED.all;

USE IEEE.STD_LOGIC_ARITH.all;

ENTITY counter IS

PORT(enable, clr : IN STD_LOGIC;

THECOUNT : OUT STD_LOGIC_VECTOR(5 downto 0));

END counter;

ARCHITECTURE a OF counter IS

SIGNAL tmp: STD_LOGIC_VECTOR(5 downto 0);

BEGIN

PROCESS(enable, CLR)

BEGIN

IF (CLR='1') THEN

tmp <= "000000";

ELSIF (enable'event and enable='1') THEN

tmp <= tmp + 1;

END IF;

end process;

THECOUNT <= tmp;

end a;

This is the code I am using to work a counter.. I use the simulator tool to discover that THECOUNT never increases after CLR goes low. THECOUNT is always 0. Is there something I am doing wrong? Thanks in advance for any help!

3 Replies

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

    Surely the problem is with simulator settings or input waveform.

    I tried to simulate your code and it works.

    I used the following stimuli:

    enable : clock signal, period 10ns

    clr : 100ns high then low

    When clr goes down, counter starts incrementing.