Packet whitening and de-whitening is possible with RADIO and is enabled in PCNF1.WHITEEN. When enabled, whitening and de-whitening will be handled by RADIO automatically as packets are sent and received.
The data whitening is done by means of a configurable linear feedback shift register in a one-to-many topology, as illustrated in the following figure. Bit 0 is used to exclusive OR (XOR) the data packet that is to be whitened or de-whitened. The linear feedback shift register is configured and initialized using the DATAWHITE register. The reset value for the DATAWHITE.POLY field is compatible with Bluetooth Low Energy. The initial vector is configured in DATAWHITE.IV.
Whitening and de-whitening will be performed over the whole packet except for the preamble and the address fields.
Including the address field in CRC check (CRCCNF.SKIPADDR = Include) is not supported for whitened packets.