VHDLでのcharacter型の使い方10選

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity char_example is
end char_example;

architecture Behavior of char_example is
    signal sample_char : character := 'A';
begin
    process
    begin
        report "Character value: " & sample_char;
        wait;
    end process;
end Behavior;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity char_manipulation is
end char_manipulation;

architecture Behavior of char_manipulation is
    signal sample_char : character := 'A';
begin
    process
    begin
        sample_char <= character'val(integer'val(sample_char) + 1);
        report "Updated character value: " & sample_char;
        wait;
    end process;
end Behavior;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity char_to_int is
    Port ( char_in : in  character;
           int_out : out integer);
end char_to_int;

architecture Behavior of char_to_int is
begin
    process(char_in)
    begin
        -- character型をinteger型に変換
        int_out <= character'pos(char_in);
    end process;
end Behavior;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity int_to_char is
    Port ( int_in  : in  integer;
           char_out: out character);
end int_to_char;

architecture Behavior of int_to_char is
begin
    process(int_in)
    begin
        -- integer型をcharacter型に変換
        char_out <= character'val(int_in);
    end process;
end Behavior;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity String_Operation is
end String_Operation;

architecture Behave of String_Operation is
    signal str : string(1 to 5) := "HELLO";
    signal result : string(1 to 5);
begin
    process
    begin
        for i in str'range loop
            if str(i) = 'L' then
                result(i) := 'R';
            else
                result(i) := str(i);
            end if;
        end loop;
        assert false report "結果の文字列: " & result severity note;
        wait;
    end process;
end Behave;

-- この例はシミュレーション環境での動作を前提としています。
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_TEXTIO.ALL;

entity Char_IO is
end Char_IO;

architecture Sim of Char_IO is
    file InFile : text;
    file OutFile : text;
    variable LineBuffer : line;
    variable InputChar : character;
    variable OutputChar : character;
begin
    process
    begin
        -- ユーザーからの入力を受け取る
        readline(InFile, LineBuffer);
        read(LineBuffer, InputChar);

        -- 入力を大文字に変換
        OutputChar := to_upper(InputChar);

        -- 結果を出力
        write(LineBuffer, OutputChar);
        writeline(OutFile, LineBuffer);

        wait;
    end process;
end Sim;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity String_Reverse is
end String_Reverse;

architecture Behave of String_Reverse is
    signal str : string(1 to 6) := "JPSEEMORE";
    signal result : string(1 to 6);
begin
    process
    begin
        for i in str'range loop
            result(str'length + 1 - i) := str(i);
        end loop;
        assert false report "逆順の文字列: " & result severity note;
        wait;
    end process;
end Behave;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity Special_Char_Operation is
end Special_Char_Operation;

architecture Behave of Special_Char_Operation is
    signal str : string(1 to 10) := "JPSEEMORE2023";
    signal result : string(1 to 4) := (others => ' ');
    variable index : integer := 1;
begin
    process
    begin
        for i in str'range loop
            if str(i) >= '0' and str(i) <= '9' then
                result(index) := str(i);
                index := index + 1;
            end if;
        end loop;
        assert false report "数字のみの文字列: " & result severity note;
        wait;
    end process;
end Behave;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity Char_Error_Example is
end Char_Error_Example;

architecture Behave of Char_Error_Example is
    signal charVar : character := 'AB'; -- エラー: character型は1文字のみを持つ
begin
end Behave;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity Char_Special_Case is
end Char_Special_Case;

architecture Behave of Char_Special_Case is
    signal charVar : character := 'a';
    signal logicVar : std_logic;
begin
    logicVar <= to_stdlogic(charVar); -- エラー: character型を直接std_logicに変換する関数は存在しない
end Behave;

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity Char_Customize is
end Char_Customize;

architecture Behave of Char_Customize is
    type char_array is array (1 to 5) of character;
    signal str : char_array := ('H','

e','l','l','o');
begin
end Behave;