NXP Semiconductors MKW01Z128, Reference Manual

Page: 99 / 884

Transceiver Digital Control and Communications
MKW01xxRM Reference Manual, Rev. 3, 04/2016
7-12 Freescale Semiconductor, Inc.
7.5.2.3 Unlimited Length Packet Format
Unlimited length packet format is selected when bit PacketFormat is set to 0 and PayloadLength is set to 0.
The user can then transmit and receive packet of arbitrary length and PayloadLength register is not used
in TX/RX modes for counting the length of the bytes transmitted/received.
In TX the data is transmitted depending on the TxStartCondition bit. On the RX side the data processing
features like Address filtering, Manchester encoding and data whitening are not available if the sync
pattern length is set to zero (
SyncOn = 0 ). The filling of the FIFO in this case can be controlled by the bit
FifoFillCondition . The CRC detection in RX is also not supported in this mode of the packet handler,
however CRC generation in TX is operational. The interrupts like CrcOk & PayloadReady are not
available either.
An unlimited length packet is made up of the following fields:
• Preamble (1010...).
• Sync word (Network ID).
• Optional Address byte (Node ID).
• Message data
• Optional 2-bytes CRC checksum (TX only)
Figure 7-12. Unlimited Length Packet Format
7.5.3 TX Processing (without AES)
In TX mode the packet handler dynamically builds the packet by performing the following operations on
the payload available in the FIFO:
• Add a programmable number of preamble bytes
• Add a programmable Sync word
• Optionally calculating CRC over complete payload field (optional length byte + optional address
byte + message) and appending the 2 bytes checksum.
• Optional DC-free encoding of the data (Manchester or whitening)
Only the payload (including optional address and length fields) is required to be provided by the user in
the FIFO.