RFM65CW Datasheet, PDF (37/71 Pages) List of Unclassifed Manufacturers – ISM RECEIVER MODULE

ADVANCED COMMUNICATIONS & SENSING
RFM65CW
DATASHEET
5. Data Processing
5.1. Overview
5.1.1. Block Diagram
Figure below illustrates the RFM65CW data processing circuit. Its role is to interface the data from the 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.
Rx
CONTROL
DIO0
DIO1
DIO2
DIO3
DIO4
Data Rx
SYNC
RECOG.
PACKET
HANDLER
FIFO
(+SR)
NSS
SPI
SCK
MOSI
MISO
Potential datapaths (data operation mode dependant)
Figure 20. RFM65CW Data Processing Conceptual View
The RFM65CW 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.
5.1.2. Data Operation Modes
The RFM65CW has two different data operation modes selectable by the user:
z _{Continuous mode: each bit received is accessed in real time at the DIO2/DATA pin. This mode may be used if adequate}
external signal processing is available.
z Packet mode (recommended): user only retrieves payload bytes from the FIFO. The packet engine automatically
removes the preamble, checks the Sync word, performs AES decryption, checks the CRC, and decodes DC-free
schemes if enabled. The uC processing overhead is hence significantly reduced compared to Continuous mode.
Depending on the optional features activated (CRC, AES, etc) the maximum payload length is limited to FIFO size, 255
bytes or unlimited.
Each of these data operation modes is described fully in the following sections.
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