I have a design with two ICs, one is a 4467 and the other is a 4362. For the purpose of this test, they're both configured as receivers on two different frequencies. The configuration relies on sync word detection because the preamble is neither standard nor long enough for the options available. Direct mode is used for packet handling.
The MCU periodically issues a START_RX to each IC to restart sync word detection. RX performance is normally pretty good, until sometime late at night, after more than 6 hours of continuous operation, when performance degrades for no apparent reason. RX still functions, but with greatly reduced sensitivity. I have reproduced this on two boards with slightly different circuit designs, so it's not a one-off. Resetting the MCU which shuts down and re-initializes both ICs fixes the issue.
Where do I look? Should I take a periodic snapshot of certain registers to see if something is not right? Which registers should I look at?
The application is AIS, so loss of sensitivity is a show stopper.
Do you see the sensitivity loss on both ICs on both frequencies?
Do you see it every day at the same time?
If you don't do it now, try to control the chips to READY before resending START_RX.
Generally it is advised to regularly reinitialize the radios to prevent any unexpected external disturbance, with a cycle time allowed by the use case.
Could you solve this already?