nRF24LE1 Nordic VLSI, nRF24LE1 Datasheet - Page 25

• Manufacturer Part Number: nRF24LE1
• Manufacturer: Nordic VLSI

nRF24LE1 Preliminary Product Specification
Dynamic Payload Length (DPL) is an alternative to static payload length. DPL enables the transmitter to
send packets with variable payload length to the receiver. This means that for a system with different pay-
load lengths it is not necessary to scale the packet length to the longest payload.
With the DPL feature the nRF24L01+ can decode the payload length of the received packet automatically
instead of using the RX_PW_Px registers. The MCU can read the length of the received payload by using
the R_RX_PL_WID command.
In order to enable DPL the EN_DPL bit in the FEATURE register must be enabled. In RX mode the DYNPD
register must be set. A PTX that transmits to a PRX with DPL enabled must have the DPL_P0 bit in DYNPD
set.
3.4.3.5
The CRC is the error detection mechanism in the packet. It may either be 1 or 2 bytes and is calculated
over the address, Packet Control Field and Payload.
The polynomial for 1 byte CRC is X
The polynomial for 2 byte CRC is X
No packet is accepted by Enhanced ShockBurst™ if the CRC fails.
Revision 1.1
Note: Always check if the packet width reported is 32 bytes or shorter when using the
R_RX_PL_WID command. If its width is longer than 32 bytes then the packet contains errors
and must be discarded. Discard the packet by using the Flush_RX command.
CRC (Cyclic Redundancy Check)
8
16
+ X
+ X
2
12
+ X + 1. Initial value 0xFF.
+ X
5
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+ 1. Initial value 0xFFFF.