Emulators Philosophy

In article <dfae8q$in4$1$8302bc10@news.demon.co.uk>, Paul E. Bennett
<peb@amleth.demon.co.uk> writes
>Tom wrote:
>
>> What are the collective's opinions regarding the use of in-circuit
>> emulators for proving safety critical embedded software?
>> 
>> I've heard from some people that they can't imagine how it could be done
>> without whereas others have never used an emulator and consider them
>> entirely unnecessary. Has JTAG rendered emulators obscelete?
>
>Emulators for difficult processor chips (those that would otherwise require 
>massive efforts to set up monitoring and trigger points) can be useful at 
>the pre-product-finishing stage when you need to confirm that the system 
>can follow the whole of its programming. However, the final testing must be 
>accomplished with the processors that will be delivered with the system, 
>especially for safety critical systems. 

Depending on MCU family this is the case. In other cases the part is not
always identical. However it can go a long way to help with the unit and
system testing. 

>This is a phased testing approach 
>and is, in my opinion, quite a valid consideration. I would not expect the 
>testing to be carried out under the emulator alone. I would hope, however, 
>that you would rather shy away from using such a complex and difficult 
>processors for a safety critical system.

All processor are complex these days. Also safety critical systems are
getting more complex.


-- 
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills  Staffs  England     /\/\/\/\/
/\/\/ chris@phaedsys.org      www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

Chris Hills wrote:

>>This is a phased testing approach
>>and is, in my opinion, quite a valid consideration. I would not expect the
>>testing to be carried out under the emulator alone. I would hope, however,
>>that you would rather shy away from using such a complex and difficult
>>processors for a safety critical system.
> 
> All processor are complex these days. Also safety critical systems are
> getting more complex.

There are still, fortunately, some processors around that are reasonably 
simple in their architecture which would be more suitable for a High 
Integrity application.

-- 
********************************************************************
Paul E. Bennett ....................<email://peb@amleth.demon.co.uk>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ....EBA. http://www.electric-boat-association.org.uk/
********************************************************************

In article <dfejk6$ggo$1$830fa17d@news.demon.co.uk>, Paul E. Bennett
<peb@amleth.demon.co.uk> writes
>Chris Hills wrote:
>
>>>This is a phased testing approach
>>>and is, in my opinion, quite a valid consideration. I would not expect the
>>>testing to be carried out under the emulator alone. I would hope, however,
>>>that you would rather shy away from using such a complex and difficult
>>>processors for a safety critical system.
>> 
>> All processor are complex these days. Also safety critical systems are
>> getting more complex.
>
>There are still, fortunately, some processors around that are reasonably 
>simple in their architecture which would be more suitable for a High 
>Integrity application.
>

Such as?

-- 
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills  Staffs  England     /\/\/\/\/
/\/\/ chris@phaedsys.org      www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

>>> What are the collective's opinions regarding the use of in-circuit
>>> emulators for proving safety critical embedded software?
>>
>>Emulators (like simulators) only serve a purpose in testing and
>>debugging, but since actual "proving" cannot ever be done by testing,
>>they are obviously useless for proving.
>>
>
> This is completely wrong. There are several SW tools that use full ICE
> for non-intrusive hard real time unit and system testing.
>

Can they be truly non-intrusive or will Heisenberg stick his oar in? 

Chris Hills <chris@phaedsys.org> wrote:
> In article <3nqjg0F2s52gU1@news.dfncis.de>, Hans-Bernhard Broeker
> <broeker@physik.rwth-aachen.de> writes

> >Emulators (like simulators) only serve a purpose in testing and
> >debugging, but since actual "proving" cannot ever be done by testing,
> >they are obviously useless for proving.

> This is completely wrong. There are several SW tools that use full ICE
> for non-intrusive hard real time unit and system testing. 

Interesting.  First you say I'm completely wrong, then you go on throwing
around arguments about something completely different.

I said: ICEs are for testing and debugging, but *not* for proving.  Care
telling what made that "completely wrong"?

-- 
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

Chris Hills wrote:

> In article <dfejk6$ggo$1$830fa17d@news.demon.co.uk>, Paul E. Bennett
> <peb@amleth.demon.co.uk> writes
>>Chris Hills wrote:
>>
>>>>This is a phased testing approach
>>>>and is, in my opinion, quite a valid consideration. I would not expect
>>>>the testing to be carried out under the emulator alone. I would hope,
>>>>however, that you would rather shy away from using such a complex and
>>>>difficult processors for a safety critical system.
>>> 
>>> All processor are complex these days. Also safety critical systems are
>>> getting more complex.
>>
>>There are still, fortunately, some processors around that are reasonably
>>simple in their architecture which would be more suitable for a High
>>Integrity application.
>>
> 
> Such as?

Many of RISC chips would be simpler than the CISC processors that many here 
seem to use. The RISC devices that I think are worth looking at are:-

   Patriot's PTSC1000
   Ultra Technology's F21
   Harris RTX2000 (if you are doing a space job for NASA)

There are probably more around and I think it is always worth looking at 
the architecture of a processor (the way ALU's and registers are used 
within the processor) when making an evaluation. I haven't looked at the 
structure of the ARM but I would expect many of the DSP processors to also 
be quite simple architectures also.

Sorry, by the way, for the delay getting back on this one but it has been 
rather hectic the past few days.

-- 
********************************************************************
Paul E. Bennett ....................<email://peb@amleth.demon.co.uk>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ....EBA. http://www.electric-boat-association.org.uk/
********************************************************************

In article <431c0c51$0$17486$ed2e19e4@ptn-nntp-reader04.plus.net>, Tom
<tlucasremoveall@thisextragubbinstoreplyautoflame.co.uk> writes
>>>> What are the collective's opinions regarding the use of in-circuit
>>>> emulators for proving safety critical embedded software?
>>>
>>>Emulators (like simulators) only serve a purpose in testing and
>>>debugging, but since actual "proving" cannot ever be done by testing,
>>>they are obviously useless for proving.
>>>
>>
>> This is completely wrong. There are several SW tools that use full ICE
>> for non-intrusive hard real time unit and system testing.
>>
>
>Can they be truly non-intrusive or will Heisenberg stick his oar in? 

There are quite a few ICE that are truly non-intrusive.

It is true they have an effect on the circuit but it is so minimal that
is it does have an effect on the system the circuit will not work in
production (or even development)  due to chip and other component
tolerances. 

The problem is working out which ICE are almost invisible and which are
not. The problem is some of the lesser ones claim near perfection so it
is sometimes difficult to tell.
 
-- 
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills  Staffs  England     /\/\/\/\/
/\/\/ chris@phaedsys.org      www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

In article <dfi582$4js$1$8302bc10@news.demon.co.uk>, Paul E. Bennett
<peb@amleth.demon.co.uk> writes
>Chris Hills wrote:
>
>> In article <dfejk6$ggo$1$830fa17d@news.demon.co.uk>, Paul E. Bennett
>> <peb@amleth.demon.co.uk> writes
>>>Chris Hills wrote:
>>>
>>>>>This is a phased testing approach
>>>>>and is, in my opinion, quite a valid consideration. I would not expect
>>>>>the testing to be carried out under the emulator alone. I would hope,
>>>>>however, that you would rather shy away from using such a complex and
>>>>>difficult processors for a safety critical system.
>>>> 
>>>> All processor are complex these days. Also safety critical systems are
>>>> getting more complex.
>>>
>>>There are still, fortunately, some processors around that are reasonably
>>>simple in their architecture which would be more suitable for a High
>>>Integrity application.
>>>
>> 
>> Such as?
>
>Many of RISC chips would be simpler than the CISC processors that many here 
>seem to use. The RISC devices that I think are worth looking at are:-
>
>   Patriot's PTSC1000
>   Ultra Technology's F21
>   Harris RTX2000 (if you are doing a space job for NASA)

Many thanks

>
>There are probably more around and I think it is always worth looking at 
>the architecture of a processor (the way ALU's and registers are used 
>within the processor) when making an evaluation. I haven't looked at the 
>structure of the ARM but I would expect many of the DSP processors to also 
>be quite simple architectures also.
>
>Sorry, by the way, for the delay getting back on this one but it has been 
>rather hectic the past few days.

Likewise.

-- 
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills  Staffs  England     /\/\/\/\/
/\/\/ chris@phaedsys.org      www.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/