Operation; Message Frame; Lin Protocol Message Frame Format: Master Header And Slave Response; Header Fields: Synch Break, Synch, And Id - Texas Instruments TMS320 Series User Manual

Operation

2 Operation
The SCI/BLIN module can be used in LIN mode or SCI (UART) mode. The enhancements for baud
generation and additional receive/transmit buffers necessary for LIN mode operation are part of the
enhanced buffered SCI/BLIN module.
Note: To make a determination of the bit value, 16 samples for each bit are taken with majority
vote on samples 8, 9, and 10.
For a detailed description of SCI/BLIN registers, see
2.1

Message Frame

The LIN protocol defines a message frame format, illustrated in
header, one response, one in-frame response space, and inter-byte spaces. In-frame-response and
interbyte spaces may be 0.
Figure 2. LIN Protocol Message Frame Format: Master Header and Slave Response
Sync Break
There is no arbitration in the definition of the LIN protocol; therefore, multiple slave nodes responding to a
header might be detected as an error.
The LIN bus is a single channel wired-AND. The bus has a binary level: either dominant for a value of 0,
or recessive for a value of 1.
2.1.1 Message Header
The header of a message is initiated by a master (see
• The synch break field signaling the beginning of a message
• The synch field conveying bit rate information of the LIN bus
• The ID field denoting the content of a message
SYNCH BREAK FIELD
12 Local Interconnect Network (LIN) Module
Preliminary
Message Frame
Master Header
Sync Field
Figure 3. Header Fields: Synch Break, Synch, and ID
Section 6.
Figure 2. Each frame includes one master
Slave Response
In-Frame Space
1, 2, 3, ...8 Data Fields
Figure 3) and consists of a three field-sequence:
SYNCH FIELD
SPRUGE2A – May 2009 – Revised June 2009
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ID FIELD
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