About MSP432 external crystal question

Hi Ashley,

Just out of curiosity, is there a particular reason you want a 48MHz clock as an external input instead of the 48MHz clock from the internal DCO?  Do you need synchronized clocks in your system?  I want to understand your use case so that I can give you the appropriate support.

As for the single-ended source, I am not sure.  I would recommend you post this question to the MSP432 specific forum, they are the MSP432 experts and can give you better advice (MSP432 forum link: here).  

Regards,

-- Emmanuel

Hi Emmanuel,
My team hardware engineer try to use ext clock on target board , but I hasn't find TI-RTOS to configure.
Can I use ext clock in MSP432 on TI-RTOS , if it's possible,how setting it ?
thanks
Ashley

Hi Ashley, besides getting more hardware information on the MSP432 forum, here's how you would set a the timer(If you're planning on using one) and BIOS CPU to the correct frequency.

Add the following code to your applications' configuration file:

var Timer = xdc.useModule('ti.sysbios.family.arm.msp432.Timer');
Timer.intFreq.hi = 0;
Timer.intFreq.lo = 48000000;

and

var BIOS = xdc.useModule('ti.sysbios.BIOS');
BIOS.cpuFreq.hi = 0;
BIOS.cpuFreq.lo = 48000000;

If you have any questions regarding this information you may also refer to the SYSBIOS API documentation within your TIRTOS installation.

Best,
Alexander

In addition to the information above, you may also reference the ClockFreqs module for the MSP432 which demonstates, in detail, how to change the clock frequencies for the device.

You can find it in your TIRTOS/SYSBIOS installation, or from here:

software-dl.ti.com/.../index.html

and navigate to ti->sysbios->family->arm->msp432->ClockFreqs.

Best,
Alexander