Block Comments (15.9)

VHDL you can use single-line comment or delimited comments.

• Single-line—These comments begin with two adjacent hyphens --, and the comment extends to the end of the line.
• Delimited—These commnents consist of text surrounded with delimiters. The comment begins with /* and continues until */

Begin	
	if A(0) then 	-- here is a single line comment
		C(0)<='1'
	else 
		C(0)<='0';
	end if;
end process;
/* here is a delimited comment 
   that spans two lines */