Product Specs

Table Of Contents
23 RADIO 2.4 GHz Radio
Page
211
P A S0 L S1 PAYLOAD CRC
(carrier)
1
3
2
CRC
PAYLO AD
S1
L
S0
A
P
(carrier)
TXDISABLE
TX
TXIDLE
TX
TXRU
3
2
1
CRC
PAYLOAD
S1
L
S0
A
P
’X’
RXDISABLE
RXIDLE
RX
RXIDLE
RXRU
Figure 37: Transmission of multiple packets
23.9 Receive sequence
Before the RADIO is able to receive a packet, it must first ramp up in RX mode
See RXRU in Figure 34: Radio states on page 209 and Figure 38: Receive sequence on page 211.
An RXRU ramp-up sequence is initiated when the RXEN task is triggered. After the 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 Figure 34: Radio states on page 209
the START task can, first be triggered after the RADIO has entered into the RXIDLE state.
Figure 38: Receive sequence on page 211 illustrates a single packet reception 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 Figure 38: Receive sequence on page 211 the
RADIO will be listening and possibly receiving undefined data, illustrated with an 'X', from START and until a
packet with valid preamble (P) is received.
Figure 38: Receive sequence
A slightly modified version of the receive sequence from Figure 38: Receive sequence on page 211 is
illustrated in Figure 39: Receive sequence using shortcuts to avoid delays on page 212 where the the
RADIO is configured to use shortcuts between READY and START, and between END and DISABLE, which
means that no delay is introduced.
Lifeline
Transm itter
State
Reception
Lifeline
TXEN
State
START
RXEN
READY
ADDRES S
READY
START
PAYLOAD
END
START
ADDRESS
ADDRES S
PAYLOAD
PAYLOAD
END
END
DISABLE
DISABLE
DISABLED
DISABLED