RFM219SW Datasheet, PDF (25/35 Pages) List of Unclassifed Manufacturers – Wireless Alarm and Security Systems

RFM219SW
Similar to the buffer mode, the data are obtained by reading the FIFO. The packet handler provides various options of decoding
and validating the incoming data. This can further reduce the work load and user program size of the MCU.
Packet Type: Fixed Length
The fixed length means that the payload length is configured into the device and will not be changed during the transmission. The
RX and TX shall have the same payload length in this case. The payload contains the optional Node ID and the Data. The
maximum payload length is limited to the FIFO size which is 32 bytes.
Preamble
Configurable
1 - 4 bytes
Optional Manchester or
data-whitening decoding
Sync
Configurable
1 - 4 bytes
Node ID
Optional
1 byte
Data
Configurable
0 - 31 bytes
Payload/FIFO
CRC calculation
Figure 24. Fixed Length Packet Structure
CRC
Optional
2 bytes
Packet Type: Variable Length
The variable length means that the payload length can vary in different frames. In this case, an additional “Length” byte is given
as the part of the payload to indicate the payload length of the current frame. The maximum payload length can be indicated by
the Length byte is 31, because the Length byte itself is not included in the calculation. For example, if the Length byte indicates
that the payload is 31 bytes, and the Node ID is supported, it means that there will be 1 byte of Node ID and 30 bytes of Data
incoming.
If the Length byte indicates that the payload length is larger than 31, which exceeds the maximum size of the FIFO minus 1, the
current packet will be discarded by the device and the Data will not be shifted into the FIFO.
Preamble
Configurable
1 - 4 bytes
Optional Manchester or
data-whitening decoding
Sync
Configurable
1 - 4 bytes
Node ID
Optional
1 byte
Length
1 byte
Data
Configurable
0 - 30 bytes
Payload/FIFO
CRC calculation
Figure 25. Variable Length Packet Structure
CRC
Optional
2 bytes
For more details of the FIFO and configuring each component of the packet handler, please refer to the “AN138
RFM219SW Configuration Guideline”.
5.10 Receiver Operation Control
Multiple options, which can be seen in “Table 10 – Operating Setting”, are available for the user to design different operating
behavior of the device. The main purpose of this is to save the power consumption of the system. It can be seen that the device
contains a sleep timer and a receive timer. Also, the device supports the well-known wake-on radio (WOR) operation. Please
refer to the document “AN138 RFM219SW Configuration Guideline” for the details introduction of the operation settings.
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