Lpc2000

--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
> --- In lpc2000@yahoogroups.com, "douglasbolton" <doug@c...> wrote:
> > I've now got it down to any write to the EXTMODE register causes 
> the 
> > processor to fail.
> > 
> > Even writing the reset value of 0x0 to it causes a problem. Below 
> is 
> > the IAR assembler used to write the register with 0x0. I can't 
see 
> > anything wrong with this. However as soon as the register is 
> written, 
> > see you later from the processor.
> > 
> > //  273 	EXTMODE = 0x0;		
> >    LDR         R3,??LPC210xInitExtIntPin_0+8  ;; 0xe01fc148
> >    MOV         R1,#+0x0
> >    STR         R1,[R3, #+0]
> > 
> > 
> > Has anybody else out there accessed the EXTMODE register on an 
> > lpc2129??
> 
> The errata sheet mentions an issue with writing to EXTPOLAR or 
> EXTMODE.
> 
> Karl Olsen


Thank you Karl. I hadn't read the the errata for a while and missed 
that one. 

Anybody else using edge sensitive interrupts should note -

Make sure you do actually write 0x0 to VPBDIV before actually writing 
to EXTMODE. If you just write to EXTMODE at reset when VPBDIV is 0x0 
there still is a problem.