Some Active-HDL questions

> Ok, but when I'm debugging, I often need to look at intermediate
> signals to see where the problem is coming from.  It would be great to
> not have to rerun the simulation to do that.  There is more than once
> that I added some signals only to find that the problem took a
> slightly different curve than the one I expected and I have to add
> more signals.  In the end I may have to run the simulation 10 or more
> times before I see the problem.

Aye, this wouldn't be uncommon if I'm tracing a fault in a reasonably
complex design.

It's a big selling point for Aldec if you don't need to re-run a sim to
add more signals. I have had a few simulations that take 10 minutes to
get to the point I'm interested in so this could have saved a _lot_ of
time.

How much is an Active HDL license (�GBP) approx ?


Nial.

On Wed, 10 Mar 2010 09:49:28 -0000, "Nial Stewart" wrote:

>> Ok, but when I'm debugging, I often need to look at intermediate
>> signals to see where the problem is coming from.  It would be great to
>> not have to rerun the simulation to do that.  There is more than once
>> that I added some signals only to find that the problem took a
>> slightly different curve than the one I expected and I have to add
>> more signals.  In the end I may have to run the simulation 10 or more
>> times before I see the problem.
>
>Aye, this wouldn't be uncommon if I'm tracing a fault in a reasonably
>complex design.

ModelSim lets you do this too - it costs disk space and
simulation speed, of course, but may still be worth it for
tough debug:

 log -r /*

Now *everything* goes in the waveform log file, and
you can add any signal you want to the waveform retrospectively.

>It's a big selling point for Aldec if you don't need to re-run a sim to
>add more signals. I have had a few simulations that take 10 minutes to
>get to the point I'm interested in so this could have saved a _lot_ of
>time.

Yup.  The log does introduce an overhead, but it's unlikely to be
worse than a factor of 2 or 3, so likely to be a win if you
initially don't know where to start looking.
-- 
Jonathan Bromley
(not connected with Mentor, but does use ModelSim quite a lot)

> ModelSim lets you do this too

I need a smiley for a red face

:-0

I started using Modelsim 15 odd years ago and am still using it in
the same way I 'picked it up'. I have often wondered if I'm
missing out on productivity enhancements.


> - it costs disk space and
> simulation speed, of course, but may still be worth it for
> tough debug:
>
> log -r /*
>
> Now *everything* goes in the waveform log file, and
> you can add any signal you want to the waveform retrospectively.
>
>>It's a big selling point for Aldec if you don't need to re-run a sim to
>>add more signals. I have had a few simulations that take 10 minutes to
>>get to the point I'm interested in so this could have saved a _lot_ of
>>time.
>
> Yup.  The log does introduce an overhead, but it's unlikely to be
> worse than a factor of 2 or 3, so likely to be a win if you
> initially don't know where to start looking.


Even debug of small modules usually takes a few iterations so this
might be a useful 'default' simulation style when using the GUI for fault
tracing. I presume for smaller designs the overhead is negligable and it's
more likely to pay off for bigger designs.

Thanks Jonathan.

(Perhaps I should RTFM).

Nial. 

On Wed, 10 Mar 2010 10:20:15 -0000, "Nial Stewart" wrote:

>(Perhaps I should RTFM).

Nah.  That would spoil all the fun, thrill of 
the chase, etc, etc.

Anyhow, there's just too much of it.  Try this 
entertaining little experiment.

1) Open a vanilla Tcl shell (if you have Tcl 
installed).  Ask it how many commands it 
knows about:
    llength [info commands]
The answer is about 86, depending on version.

2) Try the same in ModelSim's Tcl console.
Be very, very afraid.
-- 
Jonathan Bromley

Nial Stewart wrote:
>> ModelSim lets you do this too
> 
> I need a smiley for a red face
> 
> :-0
> 
> I started using Modelsim 15 odd years ago and am still using it in
> the same way I 'picked it up'. I have often wondered if I'm
> missing out on productivity enhancements.
> 
> 
>> - it costs disk space and
>> simulation speed, of course, but may still be worth it for
>> tough debug:
>>
>> log -r /*
>>
>> Now *everything* goes in the waveform log file, and
>> you can add any signal you want to the waveform retrospectively.
>>

I had a quick look in aldec, and it has a command

log -r *

According to the help this is a synonym for

trace -r *

There are also various settings on the Trace/Debugging tab to do with 
how Aldec preserves the signals you've added to the wavefrom window,

regards
Alan

<snip>

> 
> (Perhaps I should RTFM).
>

That's what I did :-;



-- 
Alan Fitch
Senior Consultant

Doulos &#4294967295; Developing Design Know-how
VHDL * Verilog * SystemVerilog * SystemC * PSL * Perl * Tcl/Tk * Project 
Services

Doulos Ltd. Church Hatch, 22 Marketing Place, Ringwood, Hampshire, BH24 
1AW, UK
Tel:  + 44 (0)1425 471223		Email: alan.fitch@doulos.com	
Fax:  +44 (0)1425 471573		http://www.doulos.com

------------------------------------------------------------------------

This message may contain personal views which are not the views of 
Doulos, unless specifically stated.

On Mar 10, 3:03=A0am, Magne Munkejord <magnem...@yahoo.no> wrote:
> rickman wrote:
> > On Mar 9, 2:13 pm, Andy Peters <goo...@latke.net> wrote:
> >> On Mar 8, 4:10 pm, "Pete Fraser" <pfra...@covad.net> wrote:
>
> >>> Thankyou everybody for your help so far.
> >>> I seem to be confused by the waveform viewer now.
> >>> My typical debug cycle in Modelsim XE uses wave.do.
> >>> I will load the sim, run wave.do to bring up the waveforms
> >>> I'm interested in, then run the sim.
> >>> If the waveforms point to mistakes I've made, I'll often
> >>> want to add a few more waveforms, save the updated
> >>> wave.do file, then re-start the sim using the new wave.do.
> >>> I can't work out how to do the equivalent in Active-HDL.
> >>> My modesim wave.do seems to work in Aldec, but I can't
> >>> see how to save it when I've added waveforms.
> >>> I can't even work out how to add waveforms reliably;
> >>> sometimes dragging signals from the structure pane to an
> >>> existing waveform viewer opens a new viewer window.
> >>> I'm also not sure which viewer I'm using (advanced or standard),
> >>> or how I control that. Sometimes the title bar says
> >>> "untitled.awc", and sometimes "untitled.asdb".
> >>> Help, I haven't felt this clueless in a long time.
> >> I had a conversation with Aldec support yesterday about this very
> >> topic.
>
> >> And I agree -- it's very confusing.
>
> >> There are two things involved with waveform display:
>
> >> a) The .asdb is the waveform data database (sorry for the redundancy).
> >> This is a compressed binary that holds all transactions on all signals
> >> in the design (not just what is displayed).
>
> > WHAT???!!! =A0Is this saying that all of the signals are there and I
> > should be able to display a new signal without rerunning the
> > simulation??? =A0I only see .aws and .adf files, no .asdb file. =A0Do I
> > have to turn a switch to get the .asdb file so I can look at what I
> > want after the simulation is complete?
>
> >> b) The .awc is the "accelerated waveform configuration" file. This is
> >> what the GUI needs to display data in the associated .asdb.
>
> >> BUT! The above files are really only so you can save a copy of a
> >> simulation run and display it later without re-running the simulation.
>
> > Well, yeah, in essence that's what I'd like to do.
>
> >> What you REALLY want is to do is this. The first time you run your
> >> simulation (after Initialize Simulation), you create a new waveform
> >> window (which will then show the "untitled.awc" in the title bar), and
> >> drag all of the signals of interest into that window.
>
> > Yes, go on!
>
> >> To save this list of signals for future simulation runs, from the
> >> Waveform window's menu, choose "Waveform -> Save To Macro." This is
> >> akin to the ModelSim menu item "Save Format As ..." and it will create
> >> a macro file with the extension .do and it will be stored, by default,
> >> in the src directory. It will also appear in the current Design in the
> >> Workspace. Once you've created the file, for future simulation runs,
> >> you can right-click on the macro file name in the Design and choose
> >> "Execute" and it will repopulate the waveform display window with your
> >> desired signals.
>
> >> What this means is that unless you really need to save the simulation
> >> waveforms, you can shitcan both the .asdb and .awc files. All you need
> >> is the macro .do file.
>
> > Ok, but when I'm debugging, I often need to look at intermediate
> > signals to see where the problem is coming from. =A0It would be great t=
o
> > not have to rerun the simulation to do that. =A0There is more than once
> > that I added some signals only to find that the problem took a
> > slightly different curve than the one I expected and I have to add
> > more signals. =A0In the end I may have to run the simulation 10 or more
> > times before I see the problem. =A0Even at 1 minute each, that can wast=
e
> > a lot of time if there is an easy way to avoid it.
>
> > So how do I get the .asdb and .awc files?
>
> > Rick
>
> It has been some time since I used ActiveHDL. From what I can remember
> you must switch to what is called "accelerated waveform". (I assume you
> are using standard.) I think this was a preference setting for the
> program itself.
> The accelerated waveform has a slightly different look, and you can't
> use it generate stimuli.
>
> Magne

Well kiss my grits!  It seems Lattice licensees are second class
citizens and the accelerated waveform viewer is not available.  No
wonder I didn't know about it.  The docs say the accelerated viewer is
the default!

Rick

> Well kiss my grits!  It seems Lattice licensees are second class
> citizens and the accelerated waveform viewer is not available.  No
> wonder I didn't know about it.  The docs say the accelerated viewer is
> the default!


Rick, is that an OEM version you're using, it's fairly standard practice
to have reduced functionality in OEM versions.

Otherwise there would be no incentive to shell out for the full version.

(Although I'm sure you knew that).


Nial.