LPC932A1 vs LPC922

Started by ericinsomewhere, May 13, 2005, 02:48:11 AM

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ericinsomewhere

I have a program with the following code to toggle P3.1.

         P3 = P3 | 0x02;
         P3 = P3 & 0xFD;
         P3 = P3 | 0x02;
         P3 = P3 & 0xFD;

And also enable output CPU CLOCK to the pin CLKOUT, P3.0.

Register TRIM and DIVM have been set in power up:

   TRIM = TRIM | 0x40;
   DIVM = 0x00;


I download the same program on LPC932A1 and LPC922, both have the same output on CLKOUT pin.

- On LPC932A1 device, P3.1 toggle in a cycle of CLKOUT, it's fine.
- On LPC922, P3.1 toggle much more slow, around 32 cycle of CLKOUT (I haven't counted the details).

Is it any register to force LPC922 to run on a divided clock cycle? How can I force it to run in full speed, same as LPC932A1?

Anybody can help?

thx.
Eric