AN2633 Freescale Semiconductor / Motorola, AN2633 Datasheet - Page 2

• Manufacturer Part Number: AN2633
• Description: LIN Drivers for SLIC Module on the MC68HC908QL4
• Manufacturer: Freescale Semiconductor / Motorola

AN2633/D
SLIC Module
LIN Communication
2
The SLIC module automates many LIN bus functions, allowing more of the
CPU and memory resources to be used for the user application. This
application note compares CPU and memory usage details among
timer-based, UART-based solutions, and SLIC-based solutions.
Other SLIC module features include:
The SLIC module is compatible with LIN 1.3 and LIN 2.0 and requires almost
no configuration code and very minimal driver code. More details of the SLIC
module are explained in
The driver has been evaluated at 9.615 kbps, 10.417 kbps, and 19.230 kbps.
A LIN network consists of a single master node and up to 15 slave nodes.
Information sent on the LIN bus is in the form of message frames, which can
be of selectable length but always have the same format. A message frame has
between 1 and 8 bytes of data in addition to the 3 bytes of control and data
security information.
Each message frame starts with the master sending out a synchronization
break signal (synchbreak field), followed by a synchronization field and a
message identifier field. The slave then responds with the data field (which can
be between 1 and 8 bytes) and then the checksum field. The synchbreak field
identifies the beginning of a new message frame and provides a regular
opportunity for the slave to synchronize on the bus clock. The synch field
contains the information for the clock synchronization and is always 0x55.
An acknowledgement procedure for correctly received LIN messages is not
defined in the LIN protocol.
LIN Drivers for SLIC Module on the MC68HC908QL4
•
•
•
•
•
•
Freescale Semiconductor, Inc.
For More Information On This Product,
Automatic LIN frame synchronization
Autobauding up to and well exceeding LIN standard bus speeds
LIN error detection
LIN message handling
Automatic checksum generation and verification (for both types)
ID parity checking
SYNCH
BREAK
Go to: www.freescale.com
HEADER
SYNCH
FIELD
INDENT
RESPONSE SPACE
Figure 1. LIN Message Frame
FIELD
MESSAGE FRAME
SLIC Module Operation, Features, and
IN-FRAME
FIELD
DATA
FIELD
DATA
RESPONSE
FIELD
DATA
INTER-BYTE
SPACE
FIELD
DATA
CHECKSUM
FIELD
INTER-FRAME
OR BREAK
SPACE
MOTOROLA
Benefits.