External Clock

[cleriton]

Hi,

I am using the KIT EVB 13213-SRB, I have a trouble for use the external clock, I select him to be source cpu clock to use the real time interrupt (RTI) with the external clock,(I just put a led to blink) but when the program is running doesn't happen nothing to the led.

I select in the RTI the external clock in the "clock settings" and put the value 32768 in the prescaler and enabled the interrupts

Could you help me?

[bigmac · Accepted solution]

Hello,

Do you also enter stop 2 mode?  If so, the external clock cannot be used for the RTI; only the internal 1kHz oscillator is available.  This must be explicitly enabled for it to continue operating in stop mode.  However, the internal oscillator is not available in normal run mode, so the external clock must then be used for the RTI.  This is one of the pecularities of the device.

If you are connecting a crystal as the external clock, the bit ICGC1_REFS must be set for the XTAL output pin to be available, for the crystal to oscillate.

Regards,

Mac