TDA5240 Datasheet, PDF (116/284 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5240
Functional Description
Combined Level and Data criterion in COO mode
On using the Wake-Up on Data criterion in COO mode, the RSSI criterion (including the
RSSI blocking window) can be applied additionally by setting the bit
x_WUC.UFFBLCOO. This means that a Wake-Up interrupt will not be generated, when
a blocking RSSI level (e.g. an interfering signal) is detected even when the Data criterion
is fulfilled.
The behavior of the additional RSSI criterion is similar to the behavior in Ultrafast Fall
Back Mode.
After the level observation time the receiver checks, if the RSSI level is within a valid
range. If RSSI is within a valid range, the state machine will go on to check the Data
criterion. If the RSSI is within a forbidden range, a new level observation time is started
(Note that no parts of the Wake-Up pattern are lost in this case, when the RSSI criterion
succeeds within the following observation time).
This will be done as long as the RSSI value is within a forbidden range and the On time
is not elapsed.
If the receiver loses synchronization within the search for the Data criterion (e.g. pattern
detection), the WU unit will be initialized and checks again for the RSSI criterion.
Instead of the additional RSSI criterion also Signal Recognition criterion can be applied.
When the Signal Recognition threshold (x_WURSSIBHy) is not exceeded at
Observation Time, the Wake-Up on Level FSM (finite state machine) and Wake-Up on
Data FSM are initialized.
If the threshold is exceeded, then the Wake-Up on Level FSM enters the READY state
and has no further impact on Wake-up search until the Wake-up unit is initialized again.
When afterwards a Data Criterion is found to be OK (e.g. pattern matches, number of
equal bits or random bits is reached), the Wake-up search is completed positively.
When a Data Criterion is found to be not OK, the Wake-up search is terminated
independent of the state of the Wake-Up on Level FSM. Therefore both FSMs are
initialized.
Data Sheet
116
V4.0, 2010-02-19