SWCU192 November 2021 CC1312R7 , CC1352P7 , CC2652P7 , CC2652R7
The energy detect scan radio operation is a background-level operation that starts with the CMD_IEEE_ED_SCAN command and uses a command structure, as given in Table 26-63.
At the start of an RX operation, the radio CPU waits for the start trigger, then programs the frequency based on the channel parameter. If channel is 0xFF, the operation keeps running on an already-configured channel. This requires that the operation follows another receive operation or a synthesizer programming operation. If the frequency synthesizer is not running, the operation ends with an error. After programming the frequency, the radio CPU configures the receiver to receive IEEE 802.15.4 packets, but it does not store any received data.
While the receiver is running, CCA is updated as described in Section 26.5.4.1.5. When the demodulator obtains sync on a frame, the PHY header is read. This is used only for determining the carrier sense based on sync found, and sync search restarts immediately afterwards.
The energy detect scan operation ends under the same conditions as the RX operation, as described in Section 26.5.4.1.4. Before the operation ends, the radio CPU writes the maximum-observed RSSI during the energy detect scan operation to maxRssi.