VHDL Error

[Matt North]

Hi,

Has anyone come across these error before;

line 273: Error, no support for non-constant parameter for attribute POS.
line 691: Error, left bound of range does not evaluate to a constant.
line 692: Error, left bound of range does not evaluate to a constant.
line 276: Error, function ASCII_conv can terminate without a return
statement.

the part of the code which is causing the error is;

process(en_int, rst, info, address)
begin
if rst='0' or int_res='0' then
address<=1;
pdata<=(others=>'0');
elsif rising_edge(en_int) then
if address<=strsize then
pdata<=ascii_conv(info(address)); --function which holds the
attribute POS.
address<=address+1;
end if;
end if;
end process;

However when address was a loop identifier in a procedure which called the
function ascii_conv in the same way as above, no errors occurred.
The function is shown below;

result:=to_bitvector(std_logic_vector(to_unsigned(character'POS(ch), 8)));

Thanks,
Matt

 

[Mike Treseler]

Matt North wrote:

Hi,

Has anyone come across these error before;

line 273: Error, no support for non-constant parameter for attribute POS.
line 691: Error, left bound of range does not evaluate to a constant.

related thread:
http://groups.google.com/groups?q=pos+lgt_vec


-- Mike Treseler