ZHCSRW7 march 2023 AFE781H1 , AFE881H1
PRODUCTION DATA
When a carrier is detected, the CD pin toggles high, and data bytes received by the modem are automatically enqueued into FIFO_H2U. This mode is the highest priority, and the device continues to remain in this mode as long as a valid carrier is present. The system controller must timely dequeue the data from the FIFO_H2U as long as CD remains high and the demodulator enqueues new data into FIFO_H2U. CD is deasserted when the level of the incoming carrier is reduced to less than the HART specification. For receive operation timing details, see Section 7.3.5.7.