14.2.2.3.6 RX_AACK Mode Timing
A timing example of an RX_AACK transaction is shown in the figure below. In this example, a data frame with an ACK request is received. The AT86RF212B changes to state BUSY_RX_AACK after SFD detection. The completion of the frame reception is indicated by an IRQ_3 (TRX_END) interrupt. The interrupts IRQ_2 (RX_START) and IRQ_5 (AMI) are disabled in this example. The ACK frame is automatically transmitted after aTurnaroundTime (12 symbols), assuming default acknowledgment frame start timing. The interrupt latency tIRQ is specified in the Digital Interface Timing Characteristicssection.
- If the AACK_ACK_TIME bit in the XAH_CTRL_1 register (XAH_CTRL_1.AACK_ACK_TIME) is set, an acknowledgment frame is sent already two or three symbol times after the reception of the last symbol of a data or MAC command frame.