Lpc2000

Douglas
  Two things to remember.
1) It will take more than two assembly instructions to toggle
an IO line in a loop.  Take a look at the assembly code produced
by the compiler to determine the instruction count.
2) the GPIO is on the VPB (VLSI Periphereal Bus) and can only be
written at the PCLK rate.  If your PCLK divider is '1' then the
processor will not have to wait.  If not '1' then the GPIO pin
cannot be updated at the CLK (~59MHz) rate.

Regards
-Bill Knight
the ARM Patch


On Wed, 05 May 2004 10:24:17 -0000, douglasbolton wrote:

I believe I've set the PLL of an lpc2106 with a 14.7 mhz crystal up 
to be 59 Mhz

However when I toggle a GPIO pin using IOSET,IOCLR,IOSET it is only 
low for approx 200 nS. I was expecting quicker than this.

Any thoughts ???