Receive Mode (Rx); Active Mode Switching Time - ST STM32WL5 Series Reference Manual

RM0453
When entering TX mode, BUSY is set. In TX mode, BUSY is cleared when the PA ramped
up and preamble transmission starts.
PA ramping
The PA ramping time can be selected while setting the output power, by Set_TxParams().
5.7.7

Receive mode (RX)

The RX mode can be requested to be entered from Standby mode. In this case, the sub-
GHz radio enters first FS mode to lock the RF-PLL, and subsequently RX mode.
In RX mode, LNA, RF-PLL and selected modem are enabled. The receive mode provides
the following operating modes:
•
Continuous mode: The sub-GHz radio remains in RX mode and waits for incoming
packets reception until the software terminates RX mode.
• Single mode: The sub-GHz radio remains in RX mode until a packet reception and
enters automatically Standby mode after.
•
Single with timeout mode: The sub-GHz radio remains in RX mode until a packet
reception or until the timeout expires, and enters automatically Standby mode after.
•
Listening mode: The sub-GHz radio repeatedly switches between RX single with
timeout mode and Sleep mode, until an IRQ is triggered.
RX mode entry is requested by Set_Rx() command.
When entering RX mode, BUSY is set. In RX mode, BUSY is cleared when the receiver is
ready to receive data.
The receiver provides a power-saving mode at the expense of reduced sensitivity. The
receiver power-saving mode is controlled by the SUBGHZ_RXGAINR register.
5.7.8

Active mode switching time

At each transaction with the sub-GHz radio (register read/write operation or mode
switching), BUSY is set during the transaction and while the sub-GHz radio is processing
the command. BUSY is cleared once the command processing is finished or reached a
stable operating mode, and the sub-GHz radio is ready to receive a new command.
All write commands activate BUSY. For read commands, BUSY remains low.
Switching time (t
operating mode, starting from the sub-GHz radio SPI NSS rising edge, ending the SPI
command transaction, until BUSY goes inactive. There is a small delay (t
sub-GHz radio SPI NSS rising edge, ending the SPI command transaction, and when BUSY
is set. The maximum time for t
) is defined as the time to process the command or reach a stable
SWMODE
is 600 ns.
SW
RM0453 Rev 1
Sub-GHz radio (SUBGHZ)
) between the
SW
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