SX1210 SEMTECH [Semtech Corporation], SX1210 Datasheet - Page 41

• Manufacturer Part Number: SX1210
• Description: Ultra-Low Power Integrated UHF Receiver
• Manufacturer: SEMTECH [Semtech Corporation]

Similar to Buffered mode operation, in Packet mode the NRZ data from the demodulator is not directly accessed by
the uC but stored in the FIFO and accessed via the SPI Data interface.
In addition, the SX1210’s packet handler performs several packet oriented tasks such as Preamble and Sync word
extraction, CRC check, dewhitening of data, address filtering, etc. This simplifies still further software and reduces
uC overhead by performing these repetitive tasks within the RF chip itself.
Another important feature is ability to empty the FIFO in Stby mode, ensuring optimum power consumption and
adding more flexibility for the software.
Note that Bit Synchronizer and Sync word recognition are automatically enabled in Packet mode.
Two types of packet formats are supported: fixed length and variable length, selectable by the
PKTParam_Pkt_format bit. The maximum size of the payload is limited by the size of the FIFO selected (16, 32, 48
or 64 bytes).
In applications where the packet length is fixed in advance, this mode of operation may be of interest to minimize
RF overhead (no length byte field is required). All nodes should be programmed with the same packet length value.
The length of the payload is set by the PKTParam_Payload_length register and is limited by the size of the FIFO
selected.
Rev 2– Sept 8
ADVANCED COMMUNICATIONS & SENSING
Data
5.5. Packet Mode
Datapath
5.5.1. General Description
5.5.2. Packet Format
th
Rx
, 2008
5.5.2.1. Fixed Length Packet Format
RECOG.
SYNC
HANDLER
PACKET
Figure 33: Packet Mode Conceptual View
SX1210
CONTROL
Page 41 of 73
(+SR)
FIFO
CONFIG
DATA
SPI
NSS_CONFIG
MISO
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SCK
MOSI
NSS_DATA
IRQ_1
IRQ_0
SX1210