I'm using the reference design (and code) of AD9364 for KC705.
I want to understand how I can read the RSSI from this. I referred UG672 (AD9364_Register_Map_Reference_Manual_UG-672.pdf) and UG673 (AD9364_Reference_Manual_UG-673.pdf) and also went through the code (function: ad9361_read_rssi).
My question is how exactly can I use the value read in 'rssi->symbol'?
UG672 mentions the following:
This register updates after every measurement interval. Typical valid range is 0 to 457(d) (for 9 bits). Resolution is 0.25 dB/LSB for 9 bits, 0.5 dB/LSB for 8 bits.
UG673 mentions the following:
The RSSI Symbol value is stored in 0.5 dB/LSB resolution. An additional LSB is also available, and if this bit is used, the resulting 9-bit word has a resolution of 0.25 dB/LSB. In either case, the range is 0 dB to −128 dB (note the negative sign).
I'm not able to understand how to match the above two range of values.
Using what conversion or formula should I convert the rssi->symbol value and represent it in dBm?
Please help me to understand this correctly.