TDA5235
Functional Description
Details on the four wake-up data criteria
Pattern Detection
The incoming signal must match a dedicated pattern of up to 8 bits or 16 chips in Wake-
Up Pattern Chip Mode. When the WUW chip counter elapses, the search is stopped. The
higher the setting of WUBCNT the longer it is possible to search for the wake-up pattern.
The minimum for the WUBCNT is 0x11!
The pattern detection is stopped either when WUW elapses, or when symbol
synchronization is lost.
The Wake-Up pattern can be extended from 16 chips to 16 bits on activation of
WUPMSEL bit (Wake-Up Pattern Bit Mode). In this Bit Mode no Code Violations (CV)
are allowed and thus Pattern Detection is aborted, when a CV is detected.
Equal Bits Detection
Wake-up condition is fulfilled if all received bits inside of WUW are either 0 or 1.
WUBCNT holds the number of required equal bits. The higher the setting of WUBCNT
the lower the number of wrong wake-ups.
Equal bits detection is stopped if a bit change or a CV has been detected, or symbol
synchronization is lost.
Random Bits Detection
Wake-up condition is fulfilled if there is no code violation inside of WUW. WUBCNT holds
the number of required Bi-phase coded bits. The higher the setting of WUBCNT, the
lower the number of wrong wake-ups.
Random bits detection is stopped if a code violation has been detected, or symbol
synchronization is lost.
Valid Data Rate Detection
Wake-up condition is fulfilled if symbol synchronization is possible inside of Sync Search
Time out (see Chapter 2.4.8.8 RUNIN, Synchronization Search Time and Inter-
Frame Time). WUBCNT is not used.
This is the weakest wake-up data criterion, and should be avoided.
Data Sheet
54
V1.0, 2010-02-19
INFINEON [ Infineon ]
