PXD20RM Datasheet, PDF (959/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

• 4-byte buffer for reception, 4-byte buffer for transmission
• 12-bit counter for timeout management
27.3 The LIN protocol
The LIN (Local Interconnect Network) is a serial communication protocol. The topology of a LIN network
is shown in Figure 27-2. A LIN network consists of:
• One master
• Several slave
• The LIN bus
A master node contains the master task as well as a slave task, all other nodes contain a slave task only.
The master node decides when and which frame shall be transferred on the bus. The slave task provides
the data to be transported by the frame.
LIN master node
LIN slave node 1
LIN slave node n
MCU
Application
LINFlexD
Controller
LIN
LIN
Rx
Tx
LIN
Transceiver
LIN
LIN Bus
Figure 27-2. LIN network topology
27.3.1 Dominant and recessive logic levels
The LIN bus defines two logic levels, “dominant” and “recessive”, as follows:
• Dominant: logical low level (0)
• Recessive: logical high level (1)
27.3.2 LIN frames
A frame consists of a header provided by the master task and a response provided by the slave task, as
shown in Figure 27-3.
Freescale Semiconductor
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
27-3