Lpc2000

Richard,

I have tried to perform an IOSET before IODIR and it had NO EFFECT.  
And the LPC2114 user's manual specifically states that performing an 
IOSET or IOCLR on pins which are inputs will have no effect.  What 
processor did you perform this on?



--- In lpc2000@yahoogroups.com, "philips_apps" <philips_apps@y...> 
wrote:
> 
> All,
>      I have verified that the port pins (GPIO) will be driven low 
if 
> they are switched to output mode.  BUT, I have also verified that 
> they will switch high if the corresponding bit in the IOSET 
register 
> is set FIRST (eg before IODIR is set to one).  This should 
eliminate 
> the aforementioned problems.
> 
> Richard
> 
> 
> 
> 
> --- In lpc2000@yahoogroups.com, "Leighton Rowe" 
<leightonsrowe@y...> 
> wrote:
> > 
> > > This could actually be a great problem I my self have created 
> > several
> > > PLC controllers where I wanted the output to be high on birth 
and 
> > when
> > > its undetermined a weak pull up insured the state.
> > 
> > Currently there are 2 Output pins on my prototype board that 
> > requires pullup resistors to work, or else I'll have no way of 
> > controlling them. 
> > 
> > > Using additional logic, transistors etc. all costs money and I 
> > actually
> > > think It's sad that Philips didn't make their hardware "the 
right 
> > way"
> > > from the start...
> > 
> > Point taken on the cost factor...unfortunately, most mcu's aren't 
> > that perfect yet because of cases where the firmware just can't 
get 
> > around critical hardware problems. That's the "give-and-take" 
> nature 
> > of the design game.