case? statement in listing 5.12

[maltaisn]

Free-Range-VHDL-book/chapter5.tex

Lines 425 to 431 in 0dff43b

	begin
	case (ABC) is
	when "100" => F_OUT <= '1';
	when "-11" => F_OUT <= '1';
	when others => F_OUT <= '0';
	end case;
	end process my_proc;

That didn't work for me when using GHDL, it outputs 0 for 011 and 111, not 1. I found this StackOverflow question mentioning that a case? statement should be used with don't cares, however that requires VHDL-2008.

[fabriziotappero]

thanks for the question.
The "don't care" (symbol "-") is valid VHDL but not very commonly used. As discussed at pag 64 it is advised not to use it because not always implemented everywhere. GHDL is great tool but not a industry reference.

What would be your suggestion?