nRF24LE1 Nordic VLSI, nRF24LE1 Datasheet - Page 42

• Manufacturer Part Number: nRF24LE1
• Manufacturer: Nordic VLSI

nRF24LE1 Preliminary Product Specification
3.4.10.7
MAX_RT IRQ is asserted if the auto retransmit counter (ARC_CNT) exceeds the programmed maximum limit
(ARC). In
removed and the MCU decides the next step in the protocol. A toggle of the rfce bit in the RFCON register
starts a new transmitting sequence of the same packet. The payload can be removed from the TX FIFO
using the FLUSH_TX command.
3.4.11
You must disable Enhanced ShockBurst™ for backward compatibility with the nRF2401A, nRF2402,
nRF24E1 and, nRF24E2. Set the register EN_AA = 0x00 and ARC = 0 to disable Enhanced ShockBurst™.
In addition, the RF Transceiver air data rate must be set to 1Mbps or 250kbps.
3.4.11.1
The ShockBurst™ packet format is described in this chapter.
to the left.
The ShockBurst™ packet format has a preamble, address, payload and CRC field that are the same as
the Enhanced ShockBurst™ packet format described in
The differences between the ShockBurst™ packet and the Enhanced ShockBurst™ packet are:
Revision 1.1
Figure 26. TX/RX cycles with ACK Payload and the according interrupts when the transmission fails. ARC
•
Figure 27. A ShockBurst™ packet compatible with nRF2401/nRF2402/nRF24E1/nRF24E2 devices.
Preamble 1 byte
PRX
MCU PTX
MCU PRX
The 9 bit Packet Control Field is not present in the ShockBurst™ packet format.
PTX
1 Radio Turn Around Delay
2 Uploading Paylod for Ack Packet
3 Delay defined by MCU on PTX side, ≥ 130us
Figure 26.
Compatibility with ShockBurst™
ShockBurst™ packet format
Two transactions where max retransmissions is reached
UL
Packet received.
IRQ: RX DR (PID=1)
Address 3-5 byte
the packet transmission ends with a MAX_RT IRQ. The payload in TX FIFO is NOT
UL
2
No address detected.
RX off to save current
TX:PID=1
RX
130us
DL
1
RX
ACK1 PAY
ARD
Auto retransmit delay
elapsed
ACK PID=1 lost
during transmission
130us
is set to 2.
42 of 191
1
TX:PID=1
Retransmit of packet
PID=1
130us
ACK PID=1 lost
during transmission
section 3.4.3 on page 23.
1
RX
ARD
Figure 27.
Payload 1 - 32 byte
RX
No address detected.
RX off to save current
≥
130us
Packet detected as
copy of previous,
discarded
shows the packet format with MSB
3
TX:PID=1
No address detected.
RX off to save current.
IRQ:MAX_RT reached
130us
1
RX
ACK1 PAY
IRQ
130us
ACK PID=1 lost
during transmission
1
CRC 1-2
RX
byte