Lpc2000

As I have not built the circuit yet and is still in layout I was 
unsure of the drive strength. So you are saying that I could "pick" 
off the 32.768KHz outside the LPC2148 and then buffer it and not 
have any start-up problems. The reason I was going to route it out 
through a GPIO was to make use of the internal buffering etc inside 
the device. But your suggested method would also be okay.
Thanks Tom.

--- In lpc2000@yahoogroups.com, Tom Walsh <tom@...> wrote:
>
> alan_in_nz wrote:
> 
> >I am using an LPC2148 with a 32.768KHz crystal on the RTC 
oscillator 
> >pins. I need to internally route the resulting 32.768KHz clock 
and 
> >output it to a GPIO pin. Is this possible? If so how and what pin 
is 
> >best to use as the output GPIO pin? The datasheet I have been 
looking 
> >at does not seem to have (as far as I can see) a detailed block 
> >diagram which shows the clock schemes for this device and how I 
could 
> >achieve this. If anyone has done this or knows how to do this I 
would 
> >appreciate the help. Thanks. Alan
> >
> >
> >  
> >
> That sounds odd.  I had to put a resistor in series with the 
crystal to 
> drop the drive level of the LPC2xxx oscilator circuit.  That 
circuit 
> should have plenty of output level to drive other logic?  If not, 
why 
> not just stick a FET into the osc circuit and buffer your 32KHz 
into 
> your other logic?
> 
> TomW
> 
> 
> >
> >
> > 
> >Yahoo! Groups Links
> >
> >
> >
> > 
> >
> >
> >  
> >
> 
> 
> -- 
> Tom Walsh - WN3L - Embedded Systems Consultant
> http://openhardware.net, http://cyberiansoftware.com
> "Windows? No thanks, I have work to do..."
> ----------------------------------------------------
>