TDA5235
Functional Description
2.4.8.5 Wake-Up Generator
A wake-up generation unit is used only in the Self Polling Mode for the detection of a
predefined wake-up criterion in the received pattern.
There are two groups of configurable wake-up criteria:
• Wake-up on Level criteria
• Wake-up on Data criteria
The search for the wake-up data criterion is started if data chip synchronization has
occurred within the predefined number of symbols, otherwise the wake-up search is
aborted. Several different wake-up patterns, like random bit, equal bit, bit pattern or bit
synchronization, are programmable.
Additional level criterion fulfilment for RSSI or Signal Recognition can lead to a fast
wake-up and to a change to Run Mode Self Polling. Whenever one of these Wake-up
Level criteria is enabled and exceeds a programmable threshold, a wake-up has been
detected.
The Wake-up Level criterion can be used very effectively in combination with the
Ultrafast Fall Back to SLEEP Mode (see Chapter 2.6.2.3) for further decreasing the
needed active time of the autonomous receive mode. A configurable observation time
for Wake-up on Level can be set in the x_WULOT register. The Wake-up on Level
criterion can be handled very quickly for FSK modulation, while in case of ASK the nature
of this modulation type has to be kept in mind.
Data Sheet
50
V1.0, 2010-02-19
INFINEON [ Infineon ]
