Lpc2000

Should designs allways follow textbooks or manuals of older processors?

Why have 2 watchdogs: internal & external, if one internal integrated
can watch both hardware & software. Integrated watchdog can be
designed functionally external to system it watches.

Designs I have worked with on my 25 years career on microprosessors
have often had tight size requirements and external components almost
allways cost also more than integrated features.

And I haven't yet seen a perfect design. All could have been made
better, if more money, time and better resources have been used, but
then they might have come too expensive or had been on market too late.
 
--- In lpc2000@yahoogroups.com, "jayasooriah" <jayasooriah@...> wrote:
>
> --- In lpc2000@yahoogroups.com, "brendanmurphy37"
> <brendanmurphy37@> wrote:
> > Watchdog's are designed (amongst other things) to recover from  
> > unknown or unpredicted problems. By definition, I can't be aware of 
> > these beforehand to allow me to "move on" as you put it.
> 
> My textbook and processor manuals say the watchdogs in CPUs are
> designed to enable recovery from software deadlocks.
> 
> If you have hardware deadlocks, and need to recover from these, you
> have need a watchdog that is external to the system that deadlocks.
> 
> Jaya
>