Lpc2000

Jaya,

I give up! I've now asked you on seven separate occasions for 
evidence to back your very specific claim that the solution I choose 
to take will not work. I'm forced to the conclusion that one of the 
following alternatives is true:

- you have some evidence, but are unwilling to share it (but why?)

- you don't believe you need evidence to back a claim (which is an 
odd position for an academic to take)

- you have no evidence (this is now my working assumption)

You characterise the solution I'm using as applying some kind of 
catch-all fix to hide behaviour that is unpredictable or poorly 
understood. I don't know of any professional engineer who works on 
this basis: I certainly would not pass for release any product that 
used arbitrary solutions to fix behaviour that wasn't fully 
characterised.

Your latest claim is that "…the behaviour of your system under these 
conditions is UNDEFINED". Based on all the available evidence, this 
is simply not true. Philips and ARM have between them have documented 
exactly what happens in exactly what circumstances.  ARM do not state 
that the VIC's behaviour is undefined. The system is not 
unpredictable or indeterminate: it always behaves the same way in 
response to the same inputs. Indeed, your own experiments have 
confirmed this documented behaviour. It calles the default interrupt 
handler in response to very specific events, which both Philips and 
you have documented.

With knowledge and understanding of this known, deterministic, 
behaviour a very simple work-around can be provided to avoid 
undesirable consequences of that behaviour. All the evidence 
(including your own!) is that such a solution is completely 
predictable, deterministic and fully characterised. 

Of course, both you and I know that I can't prove this last 
statement: there could be some set of inputs that make the system 
behave in some unpredicted or undefined way. It's very easy to prove 
the opposite though: all you have to do is provide some evidence of 
it failing to work as predicted. Unfortunately, you don't seem to 
have any such evidence. My conclusion is that until you or someone 
else can provide any, the solution I'm using is sound. 

I've no intension of asking you an eighth time to back your claim: 
I'm tired and have had enough.

Best wishes,

Brendan

--- In lpc2000@yahoogroups.com, Jayasooriah <jayasooriah@...> wrote:
>
> Dear Ralph,
> 
> You started well but took a wrong turn.  This caused the flurry of 
noisy 
> responses from the usual suspects.
> 
> Please refer to my reply by way of annotation (with noise deleted).
> 
> It would be nice if how could point out how you came that wrong 
conclusion 
> (which I have clearly marked as "WRONG") so that I can fix it at 
the source.
> 
> Kind regards,
> 
> Jaya
> 
>