Datasheet
Table Of Contents
- 1. General Description
- 2. Electrical Characteristics
- 3. SX1272/73 Features
- 4. SX1272/73 Digital Electronics
- 4.1. The LoRaTM Modem
- 4.2. FSK/OOK Modem
- 4.2.1. Bit Rate Setting
- 4.2.2. FSK/OOK Transmission
- 4.2.3. FSK/OOK Reception
- 4.2.4. Operating Modes in FSK/OOK Mode
- 4.2.5. General Overview
- 4.2.6. Startup Times
- 4.2.7. Receiver Startup Options
- 4.2.8. Receiver Restart Methods
- 4.2.9. Top Level Sequencer
- 4.2.10. Data Processing in FSK/OOK Mode
- 4.2.11. FIFO
- 4.2.12. Digital IO Pins Mapping
- 4.2.13. Continuous Mode
- 4.2.14. Packet Mode
- 4.2.15. io-homecontrol® Compatibility Mode
- 4.3. SPI Interface
- 5. SX1272/73 Analog & RF Frontend Electronics
- 6. Description of the Registers
- 7. Application Information
- 8. Packaging Information
- 9. Revision History
www.semtech.comPage 61
SX1272/73
WIRELESS, SENSING & TIMING DATASHEET
Rev. 2 - July 2014
©2014 Semtech Corporation
4.2.10. Data Processing in FSK/OOK Mode
4.2.10.1. Block Diagram
Figure below illustrates the SX1272/73 data processing circuit. Its role is to interface the data to/from the modulator/
demodulator and the uC access points (SPI and DIO pins). It also controls all the configuration registers.
The circuit contains several control blocks which are described in the following paragraphs.
Figure 26. SX1272/73 Data Processing Conceptual View
The SX1272/73 implements several data operation modes each with their own data path through the data processing
section. Depending on the data operation mode selected some control blocks are active whilst others remain disabled.
4.2.10.2. Data Operation Modes
The SX1272/73 has two different data operation modes selectable by the user:
Continuous mode: each bit transmitted or received is accessed in real time at the DIO2/DATA pin. This mode may be
used if adequate external signal processing is available.
Packet mode (recommended): user only provides/retrieves payload bytes to/from the FIFO. The packet is automatically
built with preamble, Sync word, and optional CRC and DC-free encoding schemes The reverse operation is performed
in reception. The uC processing overhead is hence significantly reduced compared to Continuous mode. Depending on
the optional features activated (CRC, etc) the maximum payload length is limited to 255, 2047 bytes or unlimited.
Each of these data operation modes is fully described in the following sections.
CONTROL
SPI
PACKET
HANDLER
SYNC
RECOG.
DIO1
MISO
MOSI
SCK
NSS
Rx
Tx
Tx/Rx
Data
FIFO
(+SR)
Potential datapaths (data operation mode dependant)
DIO2
DIO0
DIO3
DIO4
DIO5