NRF52820-QDAA-R datasheet(168/437 Pages) NORDIC

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Peripherals

TXRU

S0 L S1

PAYLOAD

CRC

TXDISABLE

S0 L S1

PAYLOAD

CRC

(carrier)

TXIDLE

Figure 55: Transmission of multiple packets

6.12.7 Receive sequence

Before RADIO is able to receive a packet, it must first ramp up in RX mode. See RXRU in Radio states on

page 166 and Receive sequence on page 168 for more information.

An RXRU ramp up sequence is initiated when the RXEN task is triggered. After RADIO has successfully

ramped up it will generate the READY event indicating that a packet reception can be initiated. A packet

reception is initiated by triggering the START task. As illustrated in Radio states on page 166, the START

task can first be triggered after RADIO has entered into the RXIDLE state.

The following figure shows a single packet reception where the CPU manually triggers the different

tasks needed to control the flow of RADIO, i.e. no shortcuts are used. If shortcuts are not used, a certain

amount of delay caused by CPU execution is expected between READY and START, and between END and

DISABLE. RADIO will be listening and possibly receiving undefined data, represented with an 'X', from

START and until a packet with valid preamble (P) is received.

RXRU

RXIDLE

S0 L S1

PAYLOAD

CRC

RXIDLE

RXDISABLE

’X’

Figure 56: Receive sequence

The following figure shows a modified version of the receive sequence, where RADIO is configured to

use shortcuts between READY and START, and between END and DISABLE, which means that no delay is

introduced.

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NRF52820-QDAA-R Datasheet(PDF) 168 Page - Nordic Semiconductor