Electronic – dsPIC 30F2020 Primary Oscillator

I haven't used the part in a while, but it should be just a case of setting the configuration bits correctly. You don't say what compiler you are using so I can't give a code example, but your compiler manual should let you know (the commands will probably be at the end of the include file)

Also, you are better off reading the 30F family reference manual (Section 7 is the Oscillator) as it's far more detailed than the datasheet.

If you let us know which compiler and maybe post the code you have already tried it would help give a more specific answer (e.g. a code example)

I notice in the table below the FPR bits are dashed out for the FRC without PLLoption, even though note 1 says the pin function is dependent on these bits (if so, how should they be set?) This seems suspicious, I think I would raise a support ticket with Microchip to see what they have to say on the matter.

You have unfortunately not learned much from your previous UART experience if that is all the code you have. Here it seems like you have used a couple of libraries (i.e header files) which has implemented all the "tricky" stuff for you.

I would suggest that you take a look in your code and open up the UART1_Init() function. This is most likely included as uart.c and uart.h, where the .c-file is the actual implementation.

Here you will find how UART actually works, and when you have learned this you can move on to other controllers. As a matter of fact, look in to all of your uart-functions and study them, finding out what every line means. This is the most common way to learn code: To study code, understanding it and write your own.