atmega32c1 ATMEL Corporation, atmega32c1 Datasheet - Page 203

• Manufacturer Part Number: atmega32c1
• Description: Atmega32m1 Automotive 8-bit Avr Microcontroller With 32k/64k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

17.3
17.3.1
17.3.2
7647A–AVR–02/08
LIN Protocol
Master and Slave
Frames
BREAK
Field
A LIN cluster consists of one master task and several slave tasks. A master node contains the
master task as well as a slave task. All other nodes contain a slave task only.
Figure 17-1. LIN cluster with one master node and “n” slave nodes
The master task decides when and which frame shall be transferred on the bus. The slave tasks
provide the data transported by each frame. Both the master task and the slave task are parts of
the Frame handler
A frame consists of a header (provided by the master task) and a response (provided by a slave
task).
The header consists of a BREAK and SYNC pattern followed by a PROTECTED IDENTIFIER.
The identifier uniquely defines the purpose of the frame. The slave task appointed for providing
the response associated with the identifier transmits it. The response consists of a DATA field
and a CHECKSUM field.
Figure 17-2. Master and slave tasks behavior in LIN frame
The slave tasks waiting for the data associated with the identifier receives the response and
uses the data transported after verifying the checksum.
Figure 17-3. Structure of a LIN frame
SYNC
Slave Task 1
Slave Task 2
Master Task
Field
master node
master task
slave task
PROTECTED
IDENTIFIER
Field
DATA-0
slave node
slave task
LIN bus
Field
1
ATmega32/64/M1/C1
DATA-n
Field
slave node
slave task
CHECKSUM
n
Field
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