Programming Help

[maratheapurv]

Hello,

I have been writing a program for the FRDM-KV31f board with MCUXPRESSO to derive the clock using the reference manual. In the program I have to loop till a certain bit is set which I am doing with the help of a bitwise operator and a mask. But the program gets stuck in these loops. I am pretty sure that there is some issue with the check condition that I have provided but am not able to figure out what exactly is. Please check the attached and help with the same.

Regards,

Apurv.

[mjbcswitzerland]

Hi

Which loop(s) does it get stuck in?

I would suggest changing checks from

        while((MCG->S & 0x20) != 32U)       
to
        while((MCG->S & 0x20) == 0)    

since the method used is (although logically correct) really begging for problems (i.e. is very error-prone).

Also
        while((MCG->S) != 8U)
        {
          //external refrence clock selected
        }
should just be looking at the mask location and not the whole register, so will probably fail. More correct is
        while((MCG->S & 0x08) == 0)
        {
          //external refrence clock selected
        }

Regards

Mark