NXP
A library implementing IEEE 802.15.4 PHY functionality for the MCR20A transceiver. The PHY sublayer provides two services: the PHY data service and the PHY management service interfacing to the PHY sublayer management entity (PLME) service access point (SAP) (known as PLME-SAP). The PHY data service enables the transmission and reception of PHY protocol data units (PSDUs) over the media (radio).
Fork of
fsl_phy_mcr20a
by 
Freescale
The Freescale PHY Layer deals with the physical burst which is to be sent and/or received. It performs modulation and demodulation, transmitter and receiver switching, fragmentation, scrambling, interleaving, and error correction coding. The communication to the upper protocol layers is carried out through the Layer 1 Interface.
The PHY Layer is capable of executing the following sequences:
- I (Idle)
- R (Receive Sequence conditionally followed by a TxAck)
- T (Transmit Sequence)
- C (Standalone CCA)
- CCCA (Continuous CCA)
- TR (Transmit/Receive Sequence - transmit unconditionally followed by either an R or RxAck)
In addition to these sequences the PHY Layer also integrates a packet processor which determines whether the packet is MAC-compliant, and if it is, whether it is addressed to the end device. Another feature of the packet processor is Source Address Matching which can be viewed as an extension of packet filtering; however its function is very specific to its intended application (data-polling and indirect queue management by a PAN Coordinator).