Question: What do I need to do to measure crystal PPM?
Answer: After powering up the radio, write 0x20 to XTAL_CTRL_ADR register. Then use a high precision frequency counter (HP53181A or eq.) to measure crystal PPM via the XOUT pin:
// XTAL_CTRL_ADR=0x20 - drives 12MHz onto XOUT pin
RadioWrite(0Ch,20h);
Expect the measurement to be within the 11,999,640Hz to 12,000,360Hz range. If the measurement falls outside the expected range verify that the crystal's load capacitance is 10pF.
