SI4468-7 Datasheet, PDF (46/57 Pages) Silicon Laboratories – Highly configurable packet handler

Si4468/7
Figure 19. Transmit Operation where first CSMA Check Fails and Second Passes
The device also supports Listen Before Talk (LBT) as defined by the ETSI EN 300 220-1 specification, which adds
a minimum (fixed) 5 ms delay in addition to a random backoff before transmission.
9.3.3. Auto-ACK
After the packet is transmitted, the transceiver has the ability to automatically receive an ACK if configured to do
so. The transceiver will listen for a properly formatted acknowledgement frame with a set timeout period. If the ACK
is received in time, the transceiver will post an interrupt depending on if the frame pending bit is set in the ACK. If
the ACK is not received in the timeout window, the transceiver will post a TX_ERROR interrupt.
9.3.4. 802.15.4 Packet Format
The device supports the frame format defined in IEEE 802.15.4 and is able to parse the field information
autonomously without host interaction. All the host needs to do is boot up in the 802.15.4 boot mode and load the
packet into the TX FIFO for transmission. For details on the 802.15.4 packet formats, please refer to the standard’s
documentation.
9.3.5. 802.15.4g CRC
The device natively supports both 2 byte and 4 byte FCS as defined in IEEE 802.15.4g in both boot modes.
9.3.6. Simultaneous Dual Sync Word
The device is capable of simultaneously searching for two sync words with each sync word being user defined and
up to 4 bytes each. One application of this is to detect packets that use forward error correction (FEC) as defined in
IEEE 802.15.4g. FEC is an optional feature in the standard is indicated in the sync word. The transceiver does not
natively support FEC. It can pass on the information on whether FEC is used or not to the host microcontroller for
further processing.
9.3.7. Address Filtering
The device supports 8 byte (EUI-64) address filtering per IEEE 802.15.4. This is a unique identifier that is used for
each node in a network. The device also supports the short address filtering defined in the 802.15.4 standard.
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Rev 1.0