Lpc2000

--- In lpc2000@yahoogroups.com, Robert Adsett <subscriptions@...> wrote:
> >In fact, if you think about this carefully, if you are using watchdog
> >timer, then you cannot use these pins for output either because these
> >have to be strapped so that it does the right thing every time the
> >watchdog fires.
> 
> Here, I agree with you.  Those are essentially dedicated inputs.  To
me it 
> looks like marketing overcame engineering sense.  Being able to
claim an 
> extra two inputs on a check sheet.  Mind you any unit that can
afford an 
> external bus should be able to afford  a '245 or similar to provide
extra 
> digital I/O if needed.

I have seen digital outputs in parts like digital potentiometers (from
Analog Devices) on SPI bus for such purposes!

> If I recall correctly ST did dedicate their 
> equivalent lines in that fashion but like I said I don't follow the
larger 
> units that closely.

I provided my OS and applications for ST10 a while back.  Although it
was an 8-bit CPU of 8086 variety, I did find it had some nice features
that were cleverly implemented and allowed me to boot load it through
serial port.

I did not like having to write the primary loader that had to be
exactly 16 bytes long, but after I did this, I was quite happy the
designers thought through how one does this in fair detail.

Jaya

PS:  My LPC world is LPC2104/5/6 and LPC2292.  Perhaps I should make
this clear in my posts next time I make an observation.