Answer

Both the Si4460/61/63 Rev C2A and Si4467/68 RevA2A chips can be configured to transmit and receive 802.15.4g compliant packets. The PHY layer of the standard is supported by HW. That includes CRC calculation (both 16- and 32-bit), data whitening, modulation type (2GFSK, 4GFSK), all sub-GHz frequency bands, PHR parsing (i.e. processing the packet header at the RX side in order to receive the right amount of bytes, select CRC type, enable/disable data whitening). There is an 802.15.4g bidirectional example project available under WDS, which is documented in AN633. Note that the MAC has to be implemented by the host MCU code, it is only the PHY that is supported by hardware.