Datasheet

603
32117D–AVR-01/12
AT32UC3C
25.6.9 LIN Mode
The LIN Mode provides Master node and Slave node connectivity on a LIN bus.
The LIN (Local Interconnect Network) is a serial communication protocol which efficiently sup-
ports the control of mechatronic nodes in distributed automotive applications.
The main properties of the LIN bus are:
• Single Master/Multiple Slaves concept
• Low cost silicon implementation based on common UART/SCI interface hardware, an
equivalent in software, or as a pure state machine.
• Self synchronization without quartz or ceramic resonator in the slave nodes
• Deterministic signal transmission
• Low cost single-wire implementation
• Speed up to 20 Kbit/s
LIN provides cost efficient bus communication where the bandwidth and versatility of CAN are
not required.
The LIN Mode enables processing LIN frames with a minimum of action from the
microprocessor.
25.6.9.1 Modes of operation
The USART can act either as a LIN Master node or as a LIN Slave node.
The node configuration is chosen by setting the MODE field in the Mode Register (MR):
• LIN Master Node (MODE=0xA)
• LIN Slave Node (MODE=0xB)
In order to avoid unpredicted behavior, any change of the LIN node configuration must be fol-
lowed by a software reset of the transmitter and of the receiver (except the initial node
configuration after a hardware reset). (See Section 25.6.9.3)
25.6.9.2 Baud Rate Configuration
See Section “25.6.1.1” on page 568.
• LIN Master Node: the baud rate is configured in the Baud Rate Generator Register (BRGR).
• LIN Slave Node: the initial baud rate is configured in BRGR, this configuration is
automatically copied in the LIN Baud Rate Register (LINBRR) when writing BRGR. After
synchronization procedure, the baud rate is updated in LINBRR.
25.6.9.3 Receiver and Transmitter Control
See Section “25.6.2” on page 572.
25.6.9.4 Character Transmission
See Section “25.6.3.1” on page 573.
25.6.9.5 Character Reception
See Section “25.6.3.7” on page 581.