Migrating Firmware from the 632XX to 637XX

Question: Can the firmware that works on the 632XX work on the 637XX without modifications?

 

Answer:

Generally, firmware that works on the 632xx should also work on the 637xx. An exception is that, on the 632xx, the XTALOUT pin can be used as a GPIO input. However, this is not an option on the 637xx. Therefore, if the 632xx design uses the XTALOUT pin as an input pin, some modifications are needed to bring the design to the 637xx.