SM1211E915TOPIC Semtech, SM1211E915TOPIC Datasheet - Page 40

• Manufacturer Part Number: SM1211E915TOPIC
• Description: KIT PICTAIL EXT FOR SX1211
• Manufacturer: Semtech
• Type: Transceiver, UHFr

Specifications of SM1211E915TOPIC

• Frequency: 915MHz
• For Use With/related Products: SX1211
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Sync word recognition (also called Pattern recognition in previous products) is activated by setting
RXParam_Sync_on. The bit synchronizer must also be activated.
The block behaves like a shift register; it continuously compares the incoming data with its internally programmed
Sync word and asserts the Sync IRQ source on each occasion that a match is detected. This is illustrated in Figure
33.
During the comparison of the demodulated data, the first bit received is compared with bit 7 (MSB) of byte at
address 22 and the last bit received is compared with bit 0 (LSB) of the last byte whose address is determined by
the length of the Sync word.
When the programmed Sync word is detected the user can assume that this incoming packet is for the node and
can be processed accordingly.
The packet handler is the block used in Packet mode. Its functionality is fully described in section 5.5.
The control block configures and controls the full chip’s behavior according to the settings programmed in the
configuration registers.
Rev 7 – Sept 2
ADVANCED COMMUNICATIONS & SENSING
Size: Sync word size can be set to 8, 16, 24 or 32 bits via RXParam_Sync_size. In Packet mode this field is
also used for Sync word generation in Tx mode.
Error tolerance: The number of errors tolerated in the Sync word recognition can be set to 0, 1, 2 or 3 via
RXParam_Sync_tol.
Value: The Sync word value is configured in SYNCParam_Sync_value. In Packet mode this field is also used
for Sync word generation in Tx mode.
(NRZ)
DCLK
Rx DATA
SYNC
5.2.3. Sync Word Recognition
5.2.4. Packet Handler
5.2.5. Control
nd
, 2008
5.2.3.1. Overview
5.2.3.2. Configuration
Sync_value[x]
Bit N-x =
Figure 33: Sync Word Recognition
Sync_value[1]
Bit N-1 =
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Sync_value[0]
Bit N =
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