RFM64W Datasheet, PDF (34/75 Pages) List of Unclassifed Manufacturers – ISM TRANSCEIVER MODULE

ADVANCED COMMUNICATIONS & SENSING
RFM 64W
5. Data Processing
5.1. Overview
5.1.1. Block Diagram
Figure 25, illustrates the RFM64W data processing circuit. Its role is to interface the data to/from the
modulator/demodulator and the uC access points (SPI, IRQ and DATA pins). It also controls all the configuration
registers.
The circuit contains several control blocks which are described in the following paragraphs.
Tx/Rx
RFM64W
CONTROL
DATA
IRQ_0
IRQ_1
Data
Rx _SYNC
RECOG.
Tx
PACKET
HANDLER
FIFO
(+SR)
SPI
CONFIG
DATA
NSS_DATA
SCK
MOSI
MISO
Figure 25: RFM64W’s Data Processing Conceptual View
The RFM64W 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 RFM64W has three different data operation modes selectable by the
user:
„ Continuous mode: each bit transmitted or received is accessed in real time at the DATA pin. This mode may be
used if adequate external signal processing is available.
„ Buffered mode: each byte transmitted or received is stored in a FIFO and accessed via the SPI bus. uC
processing overhead is hence significantly reduced compared to Continuous mode operation. The packet
length is unlimited.
„ 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, DC free encoding and the reverse operation is
performed in reception. The uC processing overhead is hence reduced further compared to Buffered mode.
The maximum payload length is limited to the maximum FIFO limit of 64 bytes
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