tda5235 Infineon Technologies Corporation, tda5235 Datasheet - Page 66

• Manufacturer Part Number: tda5235
• Description: Enhanced Sensitivity Double-configuration Receiver With Digital Baseband Processing
• Manufacturer: Infineon Technologies Corporation

Message ID Scanning is aborted immediately by the Master FSM, if symbol
synchronization is lost or an EOM (End Of Message) is detected.
Example:
Start Selection: 00010001b
Number to scan: 00b, 01b, 10b, 11b
Figure 37
The starting position in this case is Bit 17. Depending on the number to scan, the
corresponding number of bytes is compared with the stored MIDs.
2.4.8.8
The functionality of the Digital Baseband Receiver is divided into four consecutive data
processing stages; the data filter, clock and data recovery, data slicer and frame
synchronization unit. The architecture of the Digital Baseband Receiver is optimized for
processing bi-phase coded data streams.
The basic structure of a payload frame is shown in
so called RUNIN. The RUNIN with the minimum length of four bi-phase coded symbols
is used for internal filter settling and frequency adjustment. The TSI (Telegram Start
Identifier), which is used as framing word, follows the RUNIN sequence. The payload
contains the effective data. The length of the valid payload data is defined as the length
itself or additional criteria (e.g. loss of Sync).
Please note that almost all transmitted protocols send a wake-up sequence before the
payload frame (see also
whether there is a suitable message available or not. Further details on this topic can be
gained from
Data Sheet
FSYNC
Number To Scan =00 b
Number To Scan =01 b
Number To Scan =10 b
Number To Scan =11 b
Bit
0
RUNIN, Synchronization Search Time and Inter-Frame Time
1
Chapter 2.6.1.5
MID Scanning
2
17 18
Start MID Scan
Figure
Byte0
Byte0
Byte0
Byte0
and
72). This wake-up sequence allows a very fast decision,
23 24 25 26
Chapter
Byte1
Byte1
Byte1
66
2.4.8.5.
31 32 33 34
Figure
Byte2
Byte2
38. The protocol starts with a
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Functional Description
Byte3
V1.0, 2010-02-19
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TDA5235