42.7 Zigbee Subsystem
The Zigbee Subsystem deals with the physical/modem layer and the MAC layer of the Zigbee transceiver. A digital baseband processor down-converts and demodulates the received IF data. The subsequent modules implement basic MAC functionality and hardware accelerators for features, such as automatic acknowledgment, CSMA_CA and retransmission or automatic FCS check. The flow control is done by a Finite State Machine (FSM). The data is stored in integrated 128-byte RX and TX frame buffers.