User Manual

Revision 1.0 Page 38 of 78
nRF24L01+ Product Specification
RX FIFO and the RX_DR IRQ is asserted. If the last received packet from the transmitter is acknowledged
with an ACK packet with payload, the TX_DS IRQ indicates that the PTX received the ACK packet with
payload. If the No_ACK flag is not set in the received packet, the PRX enters TX mode. If there is a pending
payload in the TX FIFO it is attached to the ACK packet. After the ACK packet is transmitted, the
nRF24L01+ returns to RX mode.
A copy of a previously received packet might be received if the ACK packet is lost. In this case, the PRX
discards the received packet and transmits an ACK packet before it returns to RX mode.