Lpc2000

At 10:32 PM 4/24/2006 +0000, rtstofer wrote:
>--- In lpc2000@yahoogroups.com, "karlstiller" <karls@...> wrote:
> > When adding the PLL or the MAM into the existing project,
> > communication on UART1 stops working.  The first byte is sent
> > correctly, but the rest of the string (sent using the interrupt
> > generated from UART1 TX) isn't sent.
> >
> > I have read the Philips datasheet, and the guide from Hitex (The
> > Insider's Guide To The Philips ARM7-Based Microcontrollers) and
> > haven't found anything relating to the MAM or PLL and its effects on
> > interrupts.
> >
> > Any ideas?
> >
> > Karl
> >
>
>But, you haven't told us the important stuff: what crystal frequency,
>what PLL setup (for a 14.7456 MHz crystal, PLLCFG=0x23 works), what
>MAM setup (MAMCR=0x02 and MAMTIM=0x04 works) and what VPBDIV (0x01 works).

You can definitely get odd behaviour if you operate the PLL outside of its 
range.  The CPU may run but the peripherals may behave strangely.  You can 
also look at the support routines in the newlib-lpc lib for an example that 
takes the crystal frequency and desired operating frequency as inputs and 
set the PLL registers accordingly.  That might give you a double check on 
your values.

Robert

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