TDA5240 Datasheet, PDF (63/284 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5240
Functional Description
2.4.8.7 Message ID Scanning
This unit is used to define an ID or special combination of bits in the payload data stream,
which identifies the pattern. All SFRs configuring the Message ID Scanning Unit feature
the Multi-Configuration capability. Furthermore, it is available in the Slave and Self
Polling Mode. The MID Unit can be mainly configured in two modes: 4-Byte and 2-Byte
organized Message ID. For each configuration there are 20 8-bit registers designed for
ID storage. SFRs are used to configure the MID Unit: Enabling of the MID scanning,
setting of the ID storage organization, the starting position of the comparison and
number of bytes to scan.
When the Message ID Scanning Unit is activated, the incoming data stream is compared
bit-wise serially with all stored IDs. If the Scan End Position is reached and all received
data have matched the observed part of at least one MID the Message ID Scanning Unit
indicates a successful MID scanning to the Master FSM, which generates an MID
interrupt.
Please note that the default register value of the MID registers is set to 0x00. All MID
registers must be set to a pattern value to avoid matching to default value 0x00.
If the MID Unit finishes ID matching without success, the data receiving is stopped and
the FSM waits again for a Frame Start criterion. The received bits are still stored in the
FIFO.
Data Sheet
63
V4.0, 2010-02-19