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-   -   Modelsim 5.7c behaviour (http://www.fpgacentral.com/group/showthread.php?t=66127)

Ingmar Seifert 10-08-2003 09:50 AM

Modelsim 5.7c behaviour
 
Hallo,

I use Modelsim 5.7c since yesterday. Before this I uses 5.6e.
I now get a warning when compiling a vhdl-file, in the following form:

WARNING[10]: E:/Hu-Moment-Berechnung/src/hu_unit.vhd(162): Synthesis
Warning: Signal "state" appears in process "steuerung"'s senstivity
list, but it is not used in the clock expression or reset expression.

I have set all signals, thta are read in a process in it's sensitivity
list. Former versions of modelsim showed an error, when the signal names
were missing. This version schows an error, when the signals are there.

What's wrong with my code or modelsim?


My code:
steuerung: PROCESS(HU_UNIT_EN, div_xs_quotient, div_xs_rdy, state,CLK,RESET)
BEGIN
IF RESET = '1' THEN
state <= IDLE;
div_xs_en <= '0';
xs_s <= (others=>'0');
ELSIF CLK'EVENT AND CLK='1' THEN
CASE state IS
-- IDLE = Startzustand nach RESET
WHEN IDLE =>
IF HU_UNIT_EN = '1' THEN
state <= XS;
END IF;
div_xs_en <= '0';

Thanks for your help in advance.
Regards,
Ingmar Seifert


Jim Wu 10-08-2003 11:52 AM

Re: Modelsim 5.7c behaviour
 

> WARNING[10]: E:/Hu-Moment-Berechnung/src/hu_unit.vhd(162): Synthesis
> Warning: Signal "state" appears in process "steuerung"'s senstivity
> list, but it is not used in the clock expression or reset expression.
>


> steuerung: PROCESS(HU_UNIT_EN, div_xs_quotient, div_xs_rdy,

state,CLK,RESET)

In a clocked process, only CLK and RESET need to be in the sensitivity list.

Jim Wu
[email protected] (remove capital letters)
http://www.geocities.com/jimwu88/chips



Allan Herriman 10-08-2003 11:57 AM

Re: Modelsim 5.7c behaviour
 
On Wed, 08 Oct 2003 10:50:04 +0200, Ingmar Seifert
<[email protected]> wrote:

>Hallo,
>
>I use Modelsim 5.7c since yesterday. Before this I uses 5.6e.
>I now get a warning when compiling a vhdl-file, in the following form:
>
>WARNING[10]: E:/Hu-Moment-Berechnung/src/hu_unit.vhd(162): Synthesis
>Warning: Signal "state" appears in process "steuerung"'s senstivity
>list, but it is not used in the clock expression or reset expression.
>
>I have set all signals, thta are read in a process in it's sensitivity
>list. Former versions of modelsim showed an error, when the signal names
>were missing. This version schows an error, when the signals are there.
>
>What's wrong with my code or modelsim?



The prevision version of Modelsim (5.6e) was wrong. The new version
(5.7c) is correct.
Previously, Modelsim would check that every signal used in the process
was in the sensitivity list. This is fine for combinatorial but wrong
for clocked processes.

Now, it can identify clocked processes (or clocked processes with
async resets), and checks that only the clocks and resets are in the
sensitivity list.

>My code:
>steuerung: PROCESS(HU_UNIT_EN, div_xs_quotient, div_xs_rdy, state,CLK,RESET)


should be:

>steuerung: PROCESS(CLK,RESET)


Regards,
Allan.


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