Datasheet

MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Freescale Semiconductor 209
Figure 12-14. Handling LIN Message Headers
12.6.7.1 LIN Message Headers
All LIN message frame headers are comprised of three components:
• The first is the SYNCHRONIZATION BREAK (SYNCH BREAK) symbol, which is a dominant
(low) pulse at least 13 or more bit times long, followed by a recessive (high) synchronization
delimiter of at least one bit time. In LIN 2.0, this is allowed to be 10 or more bit times in length.
• The second part is called the SYNCHRONIZATION FIELD (SYNCH FIELD) and is a single byte
with value 0x55. This value was chosen as it is the only one which provides a series of five falling
(recessive to dominant) transitions on the bus.
PROCESS ERROR CODE:
LIN MESSAGE
HEADER RECEIVED
SLIC UPDATES SLCBT
ID ARRIVING IN RX BUFFER
N
Y
ERROR CODE
?
Y
N
ID FOR THIS
?
N
Y
NODE
INTERRUPT
PROCESS VALID ID
BYTE FRAMING ERROR
PROCESS ERROR CODE:
IDENTIFIER-PARITY ERROR
SET IMSG BIT
BYTE FRAMING ERROR
EXIT ISR
RETURN TO
READ ID FROM SLCID
READ SLCSV
LIN BUS IDLE
VALID BREAK
AND SYNCH
DATA?
INTERRUPT
READ SLCSV
CLEAR SLCF
CLEAR SLCF
CLEAR SLCF