TDA5240 Datasheet, PDF (118/284 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5240
Functional Description
At the end of the observation time the RSSI peak tracking value of RSSIPWU signal is
compared to the 3 thresholds. Then the decision is made. The algorithmic description is
as follows (see also Figure 10, Chapter 2.4.7 RSSI Peak Detector and
Chapter 2.4.8.5 Wake-Up Generator):
if (RSSIPWU_value > x_WURSSITHy) and (RSSIPWU_value < x_WURSSIBLy or
RSSIPWU_value > x_WURSSIBHy)
then WU
else NOT
Instead of the RSSI criterion also Signal Recognition criterion can be applied. When the
Signal Recognition threshold (x_WURSSIBHy) is not exceeded at Observation Time,
then the system goes back to SLEEP or the Wake-Up on Level FSM (finite state
machine) is initialized and a Wake-up search is performed on the next specified
channel/configuration.
WULCUFFB
RSSI
4
WU on Level Criterion
Signal
Recognition
5
Sync
3
Random Bits
1
WU on Data Criterion
Equal Bits
2
Pattern
0
WUCRT (2)
WUCRT (1)
WUCRT (0)
WUCRT
&
UFFBLCOO
Figure 83
FFB is selected
UFFB activation
0
1
&
UFFB criterion
&
WU criterion
Wake-up
Generation
FSM
The On and Off time setting is different from the Constant On-Off Time Mode. The entire
On time is defined in the SPMONTA0 and SPMONTA1 registers. Regardless of the
Data Sheet
118
V4.0, 2010-02-19