TDA5240 Datasheet, PDF (109/284 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5240
Functional Description
While the TDA5240 is in Run Mode Self Polling, further Wake-ups would normally not be
detected by the receiver. If the functionality of a parallel Wake-up search during the
search for a TSI is desired, this can be activated by the PWUEN bit. In this case the
Wake-up search is not active during a recognized payload and is only active after the
first received payload frame, as can be seen from Figure 77. This feature can only be
used, when modulation type is the same for SPM and RMSP.
So after a reception of the EOM from the current payload, the parallel WU search can
take place in this mode. The WU search will be active after Symbol Sync has been
detected. The WU search will be active until the Synchronization gets lost or wake-up is
generated. After the Synchronization gets lost the WU search will be finished and wake-
up can not be detected any more (the TSI search continues as usual).
Following procedure can be applied with help of 3 SPI Write command sequences.
The idea is to generate external EOM every time the Symbol Sync goes to inactive state
and no interrupt (TSI or WU) has been detected. This will bring the MCU to the cycle start
and reinitialize the WU search.
Configuration:
Write x_WUC.PWUEN = 1
// Enable Parallel Wake-up search
Write x_WURSSITHx 0xFF
// Set RSSI threshold to max value (avoid WU during the reinitialization procedure)
Write x_WULOT 0xFF
// Set WULOT to max value (avoid WU during the reinitialization procedure)
Data Sheet
109
V4.0, 2010-02-19