Dear All,
Need some advice, I’m fairly new to this. I’m using an xc65108 chip to control some fairly simple things, programming in ISE 13.1 This is my dilemma:
In the entity top_level I’ve declare an in signal, further down in the “architecture Behavioral of top_level” I read the signal in an if loop. When I compile the code I get the following warning
“WARNING:Xst:647 - Input <BIT_1> is never used. This port will be preserved and left unconnected if it belongs to a top-level block or it belongs to a sub-block and the hierarchy of this sub-block is preserved.”
How do I get the code to understand that the signal is being used? What am I doing wrong? I do something similar with another signal declared and used in an if loop, but it does not give me any warnings there. Do I have to declare it in another form? Any input will be greatly appreciated because I’ve gone blind here and can’t see the problem. Thank you!
/Polly
Example
Entity :
BIT_1 : in STD_LOGIC;
STATUS_5V : in STD_LOGIC;
STATUS_1 : inout STD_LOGIC;
STATUS_2 : inout STD_LOGIC;
RADAR_OK : inout STD_LOGIC;
Behavioral:
--this code doesn’t generate warnings
process (STATUS_5V, R_OK)
begin
if (STATUS_5V = '1') then
R_OK <= '0';
else
R_OK <= '1';
end if;
end process;
--this gives me the WARNING: Xst:647
process (BIT_1, STATUS_1, STATUS_2)
begin
if (BIT_1 = '1') then
STATUS_1 <= '1';
else
STATUS_2 <= '1';
end if;
end process;
