Hello TI,
I have a problem to understand the frequency compensation mechanism of the cc1120. The user guide is not informative at this point.
Where does the value of the FREQOFF_EST come from? If I switch OFF the FREQOFF_CFG.FOC_EN, I still get values in FREQOFF_EST. It looks like FREQOFF_EST has nothing to do with the "other" offset compensation. Is there an other offset compensation?
The reason of my question is as follows:
I want to use the FREQOFF1 and FREQOFF0 to compensate static crystal deviation. For example to calibrate the CC1120 to a fixed frequency, regardless of the crystal deviation. For the additional deviation regarding temperature and voltage I want to use the automatic frequency compensation presented with the register FREQOF_EST.
I understood:
RF-Frequency = FREQ[2-0] + FREQOFF[1-0](my calculated offset)
What is if the FREQOFF_EST tells me 0x000D?
a) RF-Frequency = FREQ[2-0] + FREQOFF[1-0](my calculated offset) + 0x000d
or b) RF-Frequency = FREQ[2-0] + new offset 0x000d
How can I get detailed description of the frequency compensation mechanism?
best regards
Nico