NRF52820-QDAA-R datasheet(167/437 Pages) NORDIC

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Peripherals

indicating that a packet transmission can be initiated. A packet transmission is initiated by triggering the

START task. The START task can first be triggered after the RADIO has entered into the TXIDLE state.

The following figure illustrates a single packet transmission where the CPU manually triggers the different

tasks needed to control the flow of the 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. As illustrated in Transmit sequence on page 167 the RADIO will by default transmit

1s between READY and START, and between END and DISABLED. What is transmitted can be programmed

through the DTX field in the MODECNF0 register.

TXRU

TXIDLE

S0 L S1

PAYLOAD

CRC

TXIDLE

TXDISABLE

(carrier)

Figure 53: Transmit sequence

The following figure shows a slightly modified version of the transmit sequence where RADIO is configured

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

introduced.

TXRU

S0 L S1

PAYLOAD

CRC

TXDISABLE

(carrier)

Figure 54: Transmit sequence using shortcuts to avoid delays

RADIO is able to send multiple packets one after the other without having to disable and re-enable the

RADIO between packets, as illustrated in the following figure.

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NRF52820-QDAA-R Datasheet(PDF) 167 Page - Nordic Semiconductor