14.3.6.3 Data Interpretation

The AT86RF212B current channel status (CCA_STATUS) and the CCA completion status (CCA_DONE) are accessible through register the TRX_STATUS register.

Note: The register bits CCA_DONE and CCA_STATUS are cleared in response to a CCA_REQUEST.

The completion of a measurement cycle is indicated by CCA_DONE = 1. If the radio transceiver detects no signal (idle channel) during the CCA evaluation period, the CCA_STATUS bit is set to one; otherwise, it is set to zero.

When using the “energy above threshold” algorithm, a received power above PCCA_ED_THRES is interpreted as a busy channel.

When using the “carrier sense” algorithm (that is CCA_MODE = 0, 2, and 3), the AT86RF212B reports a busy channel upon detection of a PHY mode specific IEEE 802.15.4 signal above RSSIBASE_VAL. The AT86RF212B is also capable of detecting signals below this value, but the detection probability decreases with decreasing signal power. It is almost zero at the radio transceivers sensitivity level (see parameter PSENS the Receiver Characteristics).