Lpc2000

Is your VPB clocking set to 1:1?

I find that the GPIO gives me what I would expect (ie correct 
mark/space ratio), though yes it is slow. The maximum I've been able 
to get out of an LPC2106 @ 60MHz is a square wave of between 3 and 
4MHz.


--- In lpc2000@yahoogroups.com, "rkdwork" <rdavis@I...> wrote:
> Hi Andreas,
> 
> I did as you suggested and the SPI works correctly at much higher 
> speeds.  Thank for your help.  This still leaves me with the 
problem 
> of a chip select signal generated by GPIO that is extremely slow 
and 
> if I follow a set too closely behind a clear, I never see the low 
> state on the signal line. Am I also doing something wrong with the 
> GPIO.  When I step through the code for manipulating the GPIO 
signal, 
> it works as I expect.
> 
> Thanks,
> Bob Davis
> 
> --- In lpc2000@yahoogroups.com, "haack0815" <lpc_arm@s...> wrote:
> > Hi Bob,
> > 
> > the maximum SCLK of the SPI Interface is 1/8 of pclk.
> > 
> > If cclk is 60MHz and pclk = cclk you get a maximum SCLK speed of 
> 7.5 MHz.
> > 
> > 
> > It seems that your cclk is 14.7 Mhz and pclk is 1/4 of cclk.
> > Setup your PLL and VPBDIV Register to the right values.
> > 
> > Andreas