LLCC68 datasheet(100/111 Pages) SEMTECH

100 / 111 page

LLCC68

Data Sheet

Rev. 1.1

DS.LLCC68.W.APP

Dec 2024

100 of 111

Semtech

LLCC68

www.semtech.com

14.3 Circuit Configuration for Basic Rx Operation

This chapter describes the sequence of operations needed to receive a frame starting from a power up. This sequence is valid for all

protocols.

After power up (battery insertion or hard reset) the chip runs automatically a calibration procedure and goes to STDBY_RC mode. This is

indicated by a low state on BUSY pin. From this state the steps are:

1. If not in STDBY_RC mode, then set the circuit in this mode with command SetStandby().

2. Define the protocol (LoRa or FSK) with command SetPacketType(...).

3. Define the RF frequency with command SetRfFrequency(...).

4. Define where the data is stored inside the data buffer in Rx with command SetBufferBaseAddress(...).

5. Define the modulation parameter according to the chosen protocol with command SetModulationParams(...)1.

6. Define the frame format to be used with command SetPacketParams(...).

7. Configure DIO and IRQ: use command SetDioIrqParams(...) to select the IRQ RxDone and map this IRQ to a DIO (DIO1 or DIO2 or

DIO3), set IRQ Timeout as well.

8. Define Sync Word value: use command WriteReg(...) to write the value of the register via direct register access.

9. Set the circuit in reception mode: use command SetRx(). Set the parameter to enable timeout or continuous mode.

10. Wait for IRQ RxDone2 or Timeout: the chip stays in Rx and looks for a new packet if the continuous mode is selected otherwise it goes

to STDBY_RC mode.

11. In case of the IRQ RxDone, check the status to ensure CRC is correct: use the command GetIrqStatus().

Note: The IRQ RxDone means that a packet has been received but the CRC could be wrong: the user must check the CRC before

validating the packet.

12. Clear IRQ flag RxDone or Timeout: use command ClearIrqStatus(). In case of a valid packet (CRC OK), get the packet length and

address of the first byte of the received payload by using the command GetRxBufferStatus(...).

13. In case of a valid packet (CRC OK), start reading the packet.

14.4 Issuing Commands in the Right Order

Most of the commands can be sent in any order except for the radio configuration commands which sets the radio in the proper operating

mode. Indeed, it is mandatory to set the radio protocol using the command SetPacketType(...) as a first step before issuing any other

radio configuration commands. In a second step, the user should define the modulation parameter according to the chosen protocol with

the command SetModulationParams(...). Finally, the user should then select the packet format with the command

SetPacketParams(...).

Note: If this order is not respected, the behavior of the device could be unexpected.

1. Please refer to Section 15.4

2. Please refer to Section 15.3

LLCC68 Datasheet(PDF) 100 Page - Semtech Corporation