Does VHDL 2008 have built in function to convert std_logic_vector to character type?

Question

What is the 'standard' way to convert an std_logic_vector value into character type? It seems that first I convert it to an integer and then to character using the ASCII table. However, I am not sure how to do this in code.

Also, what is the 'standard' way to do the reverse conversion from character to std_logic_vector?

Some answers on the internet are quite old. This question is about the current form of the VHDL language and its libraries.

Answer 1

In terms of standard, character is an enumerated type which maps to ISO-8859-1 (i.e. ASCII for codes 0-127).

There are standard predefined attribute functions on enumerated types that can convert between enumerated value and its position in enumeration ('pos() and 'val()), then, character conversion to its 8-bit encoding is simple enough:

  subtype byte is std_ulogic_vector(7 downto 0);

  function to_byte(c : character) return byte is
  begin
    return byte(to_unsigned(character'pos(c), 8));
  end function;

  function to_character(b: byte) return character is
  begin
    return character'val(to_integer(unsigned(b)));
  end function;