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Altera_Forum
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15 years ago

VHDL_Debugging help

I'm trying to write some VHDL code for a 3 to 8 decoder, but I get the same error all the time what is wrong with my code, I have also attached a screen shot of the program and errors.

library IEEE;

use IEEE.std_logic_1164.all;

ENTITY 3to8decoder IS

PORT (

A,B,C :IN std_logic;

Y :OUT std_logic_vector (7 DOWNTO 0));

END 3to8decoder;

ARCHITECTURE decoder_C OF 3to8decoder IS

signal ABC: std_logic_vector(2 DOWNTO 0);

BEGIN

ABC <= A & B & C;

WITH ABC select Y <=

“00000001” WHEN “000”,

“00000010” WHEN “001”,

“00000100” WHEN “010”,

“00001000” WHEN “011”,

“00010000” WHEN “100”,

“00100000” WHEN “101”,

“01000000” WHEN “110”,

“10000000” WHEN other;-----> the error is here it says there is a syntax error.

END decoder_C;

Thank you

Heath

4 Replies

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

    single quotes is for single characters

    double quotes is for strings
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    I'm still getting errors I changed all the double " to single, and got less errors, stille getting 4 thow.

    library IEEE;

    use IEEE.std_logic_1164.all;

    ENTITY decoder3to8 IS

    PORT (

    A,B,C :IN std_logic;

    Y :OUT std_logic_vector (7 DOWNTO 0));

    END decoder3to8;

    ARCHITECTURE decoder_C OF decoder3to8 IS

    signal ABC: std_logic_vector(2 DOWNTO 0);

    BEGIN

    ABC <= A & B & C;

    WITH ABC select

    Y <= '00000001' WHEN '000', --here is the error and line:Error (10500): VHDL syntax error at 3to8decoder.vhd(14) near text "'"; expecting "(", or an identifier, or unary operator

    '00000010' WHEN '001',

    '00000100' WHEN '010',

    '00001000' WHEN '011',

    '00010000' WHEN '100',

    '00100000' WHEN '101',

    '01000000' WHEN '110',

    '10000000' WHEN others;

    END decoder_C;