Keyword: FUNCTION
A function statement defines a group of sequential statements that return a single value.
A function specification includes—in this order—the reserved word "function", the function’s name, a parameter list (which can only include constants and signal objects, and must all be of mode in), the reserved word "return", and the type of the value to be returned by the function.
Example
function to_unsigned (a: std_ulogic_vector)
return integer is
alias av: std_ulogic_vector (1 to a'length) is a;
variable ret,d: integer;
begin
d := 1;
ret := 0;
for i in a'length downto 1 loop
if (av(i) = '1') then
ret := ret + d;
end if;
d := d * 2;
end loop;
return ret;
end to_unsigned;
LRM
2.1
See also
