Semtech LR1121 - Lrfhsssetsyncword; Circuit Configuration for Long Range FHSS Transmission; Table 8-25: Lrfhsssetsyncword Command

LR1121
User Manual Rev 1.1
UM.LR1121.W.APP Mar 2023
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8.7.3 LrFhssSetSyncWord
Command LrFhssSetSyncWord(...) sets the LR-FHSS Syncword
Syncword: LR-FHSS Syncword. Default value is {0x2C, 0x0F, 0x79, 0x95}.
8.7.4 Circuit Configuration for Long Range FHSS Transmission
After power up (battery insertion or hard reset) the LR1121 runs automatically a calibration procedure and goes to
STDBY_RC mode. This is indicated by a low state on BUSY pin.
From STDBY_RC, the sequence of operations needed to transmit a Long Range FHSS packet are:
1. If not in STDBY_RC mode, then set the circuit in this mode with the command SetStandby(...).
2. Set the basic configuration parameters such as RF switch, PA configuration, OCP, TxParams, RfFrequency...
3. Define the modulation (LR-FHSS) with the command SetPacketType(...).
4. Set the modulation parameters (SetModulationParams(...) command) with the proper Bit Rate (488.28125 bps),
the proper Pulse Shape.
5. Call the command LrFhssBuildFrame(...).
6. Activate the IRQ: TxDone.
7. Set the circuit in transmitter mode to start transmission with the command SetTx(...).
8. Wait for TxDone interrupt.
If configured, LrFhssHop IRQ is asserted at each frequency hop inside the LR-FHSS packet, after each PA ramp-up.
Table 8-25: LrFhssSetSyncWord Command
Byte 0 1 2 3 4 5
Data from Host 0x02 0x2D Syncword[0] Syncword[1] Syncword[2] Syncword[3]
Data to Host Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)